diff --git a/src/container_range.cc b/src/container_range.cc
index b124652..8e48c59 100644
--- a/src/container_range.cc
+++ b/src/container_range.cc
@@ -34,7 +34,8 @@ namespace MultiArrayTools
 
     template <class... Indices>
     template <class MRange>
-    ContainerIndex<Indices...>::ContainerIndex(const std::shared_ptr<MRange>& range)
+    ContainerIndex<Indices...>::ContainerIndex(const std::shared_ptr<MRange>& range) :
+	IndexInterface<std::tuple<decltype(Indices().meta())...> >(range, 0)
     {
 	PackNum<sizeof...(Indices)-1>::construct(mIPack, *range);
 	IB::mPos = PackNum<sizeof...(Indices)-1>::makePos(mIPack);
@@ -93,24 +94,31 @@ namespace MultiArrayTools
     }
 
     template <class... Indices>
-    size_t ContainerIndex<Indices...>::pos() const
+    ContainerIndex<Indices...>& ContainerIndex<Indices...>::sync()
     {
 	if(mExternControl){
 	    IB::mPos = PackNum<sizeof...(Indices)-1>::makePos(mIPack);
 	}
-	return IB::mPos;
+	return *this;
     }
-
+    
+    template <class... Indices>
+    template <size_t N>
+    auto ContainerIndex<Indices...>::get() const -> decltype( *std::get<N>( mIPack ) )&
+    {
+	return *std::get<N>( mIPack );
+    }
+        
     template <class... Indices>
     bool ContainerIndex<Indices...>::first() const
     {
-	return pos() == 0;
+	return IB::pos() == 0;
     }
 
     template <class... Indices>
     bool ContainerIndex<Indices...>::last() const
     {
-	return pos() == IB::mRangePtr->size() - 1;
+	return IB::pos() == IB::mRangePtr->size() - 1;
     }
 
     
@@ -119,8 +127,14 @@ namespace MultiArrayTools
     {
 	PackNum<sizeof...(Indices)-1>::swapIndices(mIPack, inds...);
 	mExternControl = true;
-	return *this;
+	return sync();
     }    
+
+    template <class... Indices>
+    ContainerIndex<Indices...>& ContainerIndex<Indices...>::operator()()
+    {
+	return sync();
+    }
     
     /*****************************
      *   ContainerRangeFactory   *
@@ -169,6 +183,20 @@ namespace MultiArrayTools
 	return PackNum<sizeof...(Ranges)-1>::getSize(mSpace);
     }
 
+    template <class... Ranges>
+    template <size_t N>
+    auto ContainerRange<Ranges...>::get() const -> decltype( *std::get<N>( mSpace ) )&
+    {
+	return *std::get<N>( mSpace );
+    }
+
+    template <class... Ranges>
+    template <size_t N>
+    auto ContainerRange<Ranges...>::getPtr() const -> decltype( std::get<N>( mSpace ) )&
+    {
+	return std::get<N>( mSpace );
+    }
+    
     template <class... Ranges>
     typename ContainerRange<Ranges...>::IndexType ContainerRange<Ranges...>::begin() const
     {
@@ -188,7 +216,7 @@ namespace MultiArrayTools
 	i = size();
 	return i;
     }
-
+    
     template <class... Ranges>
     std::shared_ptr<IndexBase> ContainerRange<Ranges...>::index() const
     {
diff --git a/src/container_range.h b/src/container_range.h
index 820d26b..473231d 100644
--- a/src/container_range.h
+++ b/src/container_range.h
@@ -48,10 +48,16 @@ namespace MultiArrayTools
 	virtual bool last() const override;
 	
 	virtual size_t dim() const override;
-	virtual size_t pos() const override; // recalculate when externalControl == true
+
+	ContainerIndex& sync(); // recalculate 'IB::mPos' when externalControl == true
+	
+	template <size_t N>
+	auto get() const -> decltype( *std::get<N>( mIPack ) )&;
 	
 	ContainerIndex& operator()(const std::shared_ptr<Indices>&... inds); // control via external indices
-	
+
+	ContainerIndex& operator()(); // -> sync; just to shorten the code
+
     };
 
     
@@ -97,9 +103,15 @@ namespace MultiArrayTools
 	virtual size_t dim() const override;
 	virtual size_t size() const override;
 
+	template <size_t N>
+	auto get() const -> decltype( *std::get<N>( mSpace ) )&;
+
+	template <size_t N>
+	auto getPtr() const -> decltype( std::get<N>( mSpace ) )&;
+	
 	virtual IndexType begin() const override;
 	virtual IndexType end() const override;
-
+	
 	virtual std::shared_ptr<IndexBase> index() const override;
 
 	friend ContainerRangeFactory<Ranges...>;
diff --git a/src/index_unit_test.cc b/src/index_unit_test.cc
index 308c393..206846c 100644
--- a/src/index_unit_test.cc
+++ b/src/index_unit_test.cc
@@ -26,6 +26,12 @@ namespace {
 	auto nptr = std::make_shared<Factory>( rs... );
 	fptr = nptr;
     }
+
+    template <typename... Ts>
+    auto mkt(Ts&&... ts) -> decltype(std::make_tuple(ts...))
+    {
+	return std::make_tuple(ts...);
+    }
     
     class IndexTest : public ::testing::Test
     {
@@ -60,12 +66,24 @@ namespace {
 
 	    swapMFactory<M3RF>(rfbptr, temp1, temp2, temp3 );
 	    m3rptr = std::dynamic_pointer_cast<M3Range>( rfbptr->create() );
+
+	    swapMFactory<MasterRF>(rfbptr, sr1ptr, m3rptr, sr2ptr);
+	    mstrptr = std::dynamic_pointer_cast<MasterRange>( rfbptr->create() );
+
+	    swapMFactory<CRF>(rfbptr, m3rptr, sr2ptr);
+	    cr1ptr = std::dynamic_pointer_cast<CRange>( rfbptr->create() );
+
+	    swapMFactory<CRF>(rfbptr, m3rptr, sr1ptr);
+	    cr2ptr = std::dynamic_pointer_cast<CRange>( rfbptr->create() );
 	}
 
 	std::shared_ptr<RangeFactoryBase> rfbptr;
 	std::shared_ptr<SRange> sr1ptr;
 	std::shared_ptr<SRange> sr2ptr;
 	std::shared_ptr<M3Range> m3rptr;
+	std::shared_ptr<MasterRange> mstrptr;
+	std::shared_ptr<CRange> cr1ptr;
+	std::shared_ptr<CRange> cr2ptr;
     };
 
     TEST_F(IndexTest, SingleIndex_SimpleCall)
@@ -101,15 +119,15 @@ namespace {
 	EXPECT_EQ(mi.pos(), 0);
 	EXPECT_EQ(mi.first(), true);
 	EXPECT_EQ(mi.last(), false);
-	EXPECT_EQ(mi.meta() == std::make_tuple('a','1','0'), true);
-	mi.at(std::make_tuple('b','1','7'));
+	EXPECT_EQ(mi.meta() == mkt('a','1','0'), true);
+	mi.at( mkt('b','1','7') );
 	EXPECT_EQ(mi.pos(), mi.max()-1);
 	EXPECT_EQ(mi.first(), false);
 	EXPECT_EQ(mi.last(), true);
 	mi = 1;
-	EXPECT_EQ(mi.meta() == std::make_tuple('a','1','7'), true);
+	EXPECT_EQ(mi.meta() == mkt('a','1','7'), true);
 	++mi;
-	EXPECT_EQ(mi.meta() == std::make_tuple('b','1','0'), true);
+	EXPECT_EQ(mi.meta() == mkt('b','1','0'), true);
 	++mi;
 	auto mi2 = m3rptr->end();
 	--mi2;
@@ -118,8 +136,75 @@ namespace {
 	--mi2;
 	EXPECT_EQ(mi == mi2, false);
 	EXPECT_EQ(mi != mi2, true);
+	auto si = sr1ptr->begin();
+	EXPECT_EQ(si == mi, false);
+	EXPECT_EQ(si != mi, true);
     }
 
+    TEST_F(IndexTest, MasterRange_Check)
+    {
+	EXPECT_EQ(mstrptr->size(), 48);
+	EXPECT_EQ(mstrptr->template get<0>().size(), 3);
+	EXPECT_EQ(mstrptr->template get<1>().size(), 4);
+	EXPECT_EQ(mstrptr->template get<2>().size(), 4);
+	EXPECT_EQ(mstrptr->dim(), 3);
+	EXPECT_EQ(mstrptr->template get<0>().dim(), 1);
+	EXPECT_EQ(mstrptr->template get<1>().dim(), 3);
+
+	auto mi = mstrptr->begin();
+	EXPECT_EQ(mi.meta() == mkt( 'e' , mkt('a', '1', '0') , 'x' ), true);
+	mi = mi.max()-1;
+	EXPECT_EQ(mi.meta() == mkt( 'n' , mkt('b', '1', '7') , 'f' ), true);
+	mi.template down<1>();
+	EXPECT_EQ(mi.meta() == mkt( 'n' , mkt('b', '1', '0') , 'f' ), true);
+	mi.template down<0>();
+	EXPECT_EQ(mi.meta() == mkt( 'b' , mkt('b', '1', '0') , 'f' ), true);
+	mi.template down<2>();
+	EXPECT_EQ(mi.meta() == mkt( 'b' , mkt('b', '1', '0') , 'l' ), true);
+	mi.template up<1>();
+	EXPECT_EQ(mi.meta() == mkt( 'b' , mkt('b', '1', '7') , 'l' ), true);
+
+	auto& subI = mi.template get<0>();
+	EXPECT_EQ(subI.meta(), 'b');
+	mi.template up<0>();
+	EXPECT_EQ(subI.meta(), 'n');
+	auto& subI2 = mi.template get<1>();
+	EXPECT_EQ(subI2.meta() == mkt('b', '1', '7'), true);
+	mi.template down<1>();
+	EXPECT_EQ(subI2.meta() == mkt('b', '1', '0'), true);
+    }
+
+    TEST_F(IndexTest, ContainerRange_Check)
+    {
+	EXPECT_EQ(cr1ptr->size(), 16);
+	EXPECT_EQ(cr2ptr->size(), 12);
+
+	auto mi = mstrptr->begin();
+	auto ci1 = cr1ptr->begin();
+	auto ci2 = cr2ptr->begin();
+
+	EXPECT_EQ(ci1.max(), 16);
+	EXPECT_EQ(ci2.max(), 12);
+	
+	ci1(mi.template getPtr<1>(), mi.template getPtr<2>());
+	ci2(mi.template getPtr<1>(), mi.template getPtr<0>());
+
+	EXPECT_EQ(ci1.pos(), 0);
+	EXPECT_EQ(ci2.pos(), 0);
+	++mi;
+	EXPECT_EQ(ci1().pos(), 1);
+	EXPECT_EQ(ci2().pos(), 0);
+	mi.template up<1>();
+	EXPECT_EQ(ci1().pos(), 5);
+	EXPECT_EQ(ci2().pos(), 3);
+	mi.template up<0>();
+	EXPECT_EQ(ci1().pos(), 5);
+	EXPECT_EQ(ci2().pos(), 4);
+	mi = mi.max()-1;
+	EXPECT_EQ(ci1().pos(), ci1.max()-1);
+	EXPECT_EQ(ci2().pos(), ci2.max()-1);
+    }
+    
 } // end namespace 
 
 int main(int argc, char** argv)
diff --git a/src/multi_range.cc b/src/multi_range.cc
index 05b04e8..55cf433 100644
--- a/src/multi_range.cc
+++ b/src/multi_range.cc
@@ -96,6 +96,13 @@ namespace MultiArrayTools
     {
 	return *std::get<N>(mIPack);
     }
+
+    template <class... Indices>
+    template <size_t N>
+    auto MultiIndex<Indices...>::getPtr() const -> decltype( std::get<N>( mIPack ) )&
+    {
+	return std::get<N>(mIPack);
+    }
     
     template <class... Indices>
     const IndexBase& MultiIndex<Indices...>::get(size_t n) const
diff --git a/src/multi_range.h b/src/multi_range.h
index c4042a5..ea8b1a5 100644
--- a/src/multi_range.h
+++ b/src/multi_range.h
@@ -49,7 +49,10 @@ namespace MultiArrayTools
 	
 	template <size_t N>
 	auto get() const -> decltype( *std::get<N>( mIPack ) )&;
-		
+
+	template <size_t N>
+	auto getPtr() const -> decltype( std::get<N>( mIPack ) )&;
+	
 	const IndexBase& get(size_t n) const;
 	
         virtual MetaType meta() const override;
diff --git a/src/pack_num.h b/src/pack_num.h
index 20d5a7c..2ba40ef 100644
--- a/src/pack_num.h
+++ b/src/pack_num.h
@@ -92,9 +92,7 @@ namespace MultiArrayHelper
 	    auto& i = *std::get<N>(iPack).get();
 	    const size_t ownPos = pos % i.max(); 
 	    i = ownPos;
-	    if(ownPos == pos){
-		PackNum<N-1>::setIndexPack(iPack, (pos - ownPos) / i.max() );
-	    }
+	    PackNum<N-1>::setIndexPack(iPack, (pos - ownPos) / i.max() );
 	}
 	
 	template <class MRange, class... Indices>
@@ -125,21 +123,21 @@ namespace MultiArrayHelper
 	static size_t makePos(const std::tuple<std::shared_ptr<Indices>...>& iPtrTup)
 	{
 	    return std::get<N>(iPtrTup)->pos() +
-		PackNum<N-1>::makePos(iPtrTup) * std::get<N-1>(iPtrTup)->max();
+		PackNum<N-1>::makePos(iPtrTup) * std::get<N>(iPtrTup)->max();
 	}
 
 	template <class Pack, class IndexType, class... Indices>
-	static void swapIndices(Pack& ipack, const std::shared_ptr<Indices>&... ninds,
-				const std::shared_ptr<IndexType>& nind)
+	static void swapIndices(Pack& ipack, const std::shared_ptr<IndexType>& nind,
+				const std::shared_ptr<Indices>&... ninds)
 	{
-	    std::get<N>(ipack).swap( nind );
+	    std::get<std::tuple_size<Pack>::value-N-1>(ipack) = nind;
 	    PackNum<N-1>::swapIndices(ipack, ninds...);
 	}
 
 	template <class... Indices>
 	static size_t blockSize(const std::tuple<std::shared_ptr<Indices>...>& pack)
 	{
-	    return std::get<sizeof...(Indices)-N-1>(pack)->size() * PackNum<N-1>::blockSize(pack);
+	    return std::get<sizeof...(Indices)-N-1>(pack)->max() * PackNum<N-1>::blockSize(pack);
 	}
 	
     };
@@ -231,13 +229,13 @@ namespace MultiArrayHelper
 	template <class Pack, class IndexType>
 	static void swapIndices(Pack& ipack, const std::shared_ptr<IndexType>& nind)
 	{
-	    std::get<0>(ipack).swap( nind );
+	    std::get<std::tuple_size<Pack>::value-1>(ipack) = nind;
 	}
 
 	template <class... Indices>
 	static size_t blockSize(const std::tuple<std::shared_ptr<Indices>...>& pack)
 	{
-	    return std::get<sizeof...(Indices)-1>(pack)->size();
+	    return std::get<sizeof...(Indices)-1>(pack)->max();
 	}
 	
     };