Their AR-10/AR-308 Upper Receiver Vise Block is machined from High-density polyethylene (HDPE) to hold your upper receiver in a bench vise without fear of crushing, marking or scratching the finish. Simply secure the assembly into your vise, slide the upper onto the block, and insert the provided locking pins.

Features:

• Fits all standard AR-10/AR-308 upper receivers
• High-density polyethylene (HDPE)
• Locking pins included
• Made in USA