The Trinity Force Upper Vise Block is a great option for AR-style upper receivers when tightening barrel nuts to the proper specifications and attaching/removing a muzzle device. It is crafted from durable black polymer and is compatible with A3 Flat-top receivers, some AR-10 receivers, AR-308 receivers.
The Trinity Force Lower Vise Block is crafted from reinforced polymer and secures an AR-15 to a bench vise using the magazine well.
