BSS means - Blade Stop Spacer. A -61 for example would be used after the series of the closer being used.
CSS means - Cush Shoe Support. A -30 for example would be used after the series of the cl...
The use of a 62A Shoe (required) would be used to mount a 4040XP Parallel Arm with a "SURFACE" GJ 70, 79, 81, 90, or 450 series stop. You would order the 4040XP with a Reg w/62A arm op...
The Von Duprin 1439 strike is designed to be used on a blade stop frame and is 1/2" in height. The 299 strike is normally used on the stop of a frame and is 13/16" in height.