This spacer allows for the use of the current 54 Reload Adapter System with the AeroTech 54/2800 casing. It is 1.823” long and is offered here separately for customers who have previously purchased the old 54mm Reload Adapter System without this spacer. This spacer in conjunction with the 54mm RAS will allow the AeroTech 54/2800 casing to be used with 54mm reload kits designed for the 54/2560 casing and the 54/1706 casing.