Brownells has been dedicated to providing gunsmiths, armorers and gun owners with the right tools for the job, our AR-15 Upper Receiver Vise Block is no exception. Made from High Density Polyethylene Pin (HDPE) with stainless pins, our vise block will hold an upper securely in a bench vise, like the Brownells Bench Vise, using the included stainless-steel pins. Our Upper Receiver Vise Block is compatible with most AR-15 upper receivers and is a must have for anyone serious about working on AR platforms.