The robust 5/16″ T-bolt slides easily into the extruded table T-slots, and is long enough to capture nearly any material up to 3″ thick. The aluminum clamping arm is 1-1/8″ wide by 5-1/4″ long, and is anodized to avoid marking of your materials. A large, knurled handle allows you to easily tighten to the desired pressure. Sold in pairs.