This 4x32 Flip Cap Set from Trijicon is compatible with Trijicon"s 4x32 ACOG scopes. These caps will protect the objective and ocular lenses of your valuable optic, and they flip up out of the way with a flick of your finger. This Trijicon Scope Accessory requires Trijicon TA91 killFLASH. ? Fits 4x32 ACOG scopes