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, don't 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.