Description Nut and Bolt Measuring Tool Set: Our nut and bolt checker set includes assortment of 36 male/female nut and bolt size checker gauges for measuring thread pitch. Use the detachable nut and bolt gauges to check, identify verify nut and bolt size. Standard SAE/Inch Metric Sizing: The nut and bolt thread sizer kit includes both SAE and metric thread checkers. The all-in-one complete nut and bolt gauge sizing tool set for plumbers, handymen, repairsmen, auto mechanics machinists worldwide. Supports Measuring in Tight Spaces: Unlike a wall mounted nut and bolt measurer or stationary nut and bolt board, each bolt and nut identifier gauge featured in our kit can be removed used to measure thread pitch in cramped or enclosed spaces. Nut and Bolt Size Guide Storage Box: Featuring clear nut and bolt labels, our gauge organizer box makes nut and bolt identification quick easy. Foam firmly holds gauges in place for organization. Red gauges are metric, blue gauges are inches.(Label sticker color random, dont accept the specified ) Please note: the physical slightly color difference or difference, does not affect the use, please do not mind, thank you! Colour:red+blue Material:aluminum Package Contents: 36 x Nut and Bolt Checker Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.