This is a correct reproduction of the US Army Regulation M1864 soft double bag knapsack. It is appropriate for CS troops. 

This knapsack is designed with two compartments for storage. One bag closes with white leather ties, the other with leather straps and buckles. There are blanket roll straps on top for carrying a blanket or greatcoat.  The back straps have scalloped ends and the brass buttons are covered with leather circles. Leather chest cross straps are attached with J-hooks on the ends which are designed to attach to the waist belt to provide extra support. The knapsack is made from canvas.

The knapsack comes complete with J-Hooks and blanket roll straps.

You can find a very useful document for how to pack and wear your knapsack HERE .