Stern Defense RAB-AD Mini Male Assembly Black 008-SD RAB-AD MINI MALE-D1-M. It is not compatible with standard AR15 rifles as it cannot retain the buffer weight and spring. Specifications for Stern Defense RAB-AD Mini Male Assembly: Manufacturer: Stern Defense Color: Black Fabric/Material: 7075 Aluminum Weight: 1.4 oz Features of Stern Defense RAB-AD Mini Male Assembly 3 steel ball detents and locking bolt for a secure lock up Package Contents: Stern Defense RAB-AD Mini Male Assembly Stern Defense 008-SD RAB-AD MINI MALE-D1-M: RAB-AD Mini Male Assembly Black