Nut & Bolt Thread Checker (Wall Mounted) The thread checker is an accurate and easy-to-use thread verifier for both nuts and bolts Conveniently assembled onto a wire loop, it is especially well suited for distinguishing between similar inch and metric Threads Each size has a nut and bolt checker on the same gauge Bolt and nut thread checker, bolt length and screw size checker in both metric and standard sizes Pre-drilled for easy mounting (top and bottom) Mounted on heavy-duty, 1/2" Sintra (PVC foam board) Overall size: 3"W x 37"L