Real Avid Smart Fit Jaws, For Use with Vice, Pipe/Barrel Fit, Gray AVSFJPF The Smart-Jaws - Tube-Fit Sleeves for Master Gun Vise - revolutionary tools designed to secure cylindrical objects with precision and ease. These upgraded vise jaws are engineered to provide an unyielding grip on suppressors" PVC" cast-iron pipe and all types of tubing. The dual-sided design offers two distinct gripping surfaces tailored for different applications. For delicate items like suppressors" the rubberized V-shaped surface provides non-marring and heat-resistant support that ensures ample gripping power without damaging your investment. When working with robust materials such as cast-iron pipe or steel tubing where marring is not a concern" simply flip the jaws to reveal a metal V-shaped surface that delivers an ultimate vice-like grip. Designed specifically for use with Master Gun Vise" these sleeves can effectively hold up to 3.75" diameters making them versatile tools in securing various sizes of cylindrical objects during maintenance or modification tasks.