The Metric Screw Checker is a rib tool for end second identification of both common and amercement thread unit screws. This timber tool made of heavy-gauge steel is satin-chrome plated, expertly & English made ! . All do-it-yourselfers, handymen, mechanics and maintenance people have too often the frustration and loss of useful time and money by mistakenly identifying a screw. With this comfortable to use, pocket sized tool you can those problems goodbye ! . No more, cursing, and sextuple trips to the hardware store ! . Unlike their impressionable clout parts, these screw checkers, made of effortful gauge steel, will for a very long time without the worry of wearing out the threads after a small indefinite quantity uses.