The Vox Blox is a unique soft-jaw tool for clamping silencers in a vise when working on them. The Vox Blox is made of high density polyethylene plastic to minimize the chances of marring the silencer finish while providing a secure grip. The Vox Blox is available in several sizes to fit different silencer outer diameters.Features :,For 1.38" Diameter Suppressors,High Density Polyethylene Plastic