The Wheeler Engineering Delta series magazine well vise block is designed to hold any standard AR-15 lower on your Tipton Best Gun Vise, or directly mounted to a bench. The block uses the magazine catch to secure the lower. The vise block has 180 degrees of rotation in 7 degree increments. There is also a built in hammer stop to protect your lower while adjusting and function testing triggers. The block is constructed of durable, solvent resistant polymer to withstand years of use. The block also features a bolt servicing portion that will lock onto the bolt to remove and replace the extractor pin. The block can also be removed from the base and clamped into a standard bench vise like a traditional block.