The rubber butt-pad 0.30" comes standard with the ctr and moe mil-spec carbine models as well as all str acs-l acs and ubrstocks and utilizes a firm rubber that is designed for enhanced shoulder purchase and improved impact/drop mitigation.May also be installed on commercial-spec moe/ctr stocks but may prohibit use of fully collapsed position.All mounting hardware included.Made in usa.*note- not compatible with moe fixed carbine stock.Firearm Type: CarbineFirearm Model: AR-PlatformMaterial: RubberFinish: Black