Nalgene Cool Stuff Neoprene 1l fits snugly around 1 liter bottle? keeps your refreshment at a refreshing temperature longer. This item works better for keeping beverages cool and has a D ring to clip onto your backpack or anywhere else.Nalgene Cool Stuff Neoprene 1l fits snugly around 1 liter bottle? keeps your refreshment at a refreshing temperature longer. This item works better for keeping beverages cool and has a D ring to clip onto your backpack or anywhere else.