This .224 cal (.223 / 5.56mm) Charlie Front Cap is a replacement or addition for the front cap that ships standard with Chimera 300 and Saker ASR suppressors. Using a .224 caliber front cap with .223/5.56x45mm ammunition can result in additional sound reduction of 2-3 dBs. Charlie accessories are compatible with Chimera 300 and Saker series (all models).