This is used for soft seat or back . Use this 15-gauge, 6-spring x 7-spring, 18" x 33" x 3" Marshall Unit when building a spring cushion unit. Coils are individually wrapped and attached with C-rings which may be cut for re-arrangement and re-attachment according to the application. This unit can be wrapped with 2 or 3 layers of cotton for a finished pillow. CALL IF NEEDING DIFFERENT SIZES. WE CAN CUSTOMIZE SIZE of width and depth, not height.