Our nut and bolt checker set includes 44 male/female nut and bolt size checkers for measuring thread pitch. Inspect, identify and verify nut and bolt dimensions using removable nut and bolt gauges. Standard SAE/Imperial and Metric Dimensions: Nut and bolt thread sizer kit includes SAE and metric thread checkers. A complete nut and bolt gauge sizing tool set for plumbers, handymen, mechanics, auto mechanics and machinists worldwide. Supports measurements in tight spaces: Unlike wall-mounted nut and bolt gauges or fixed nut and bolt plates, each bolt and nut identifier in our kit can be disassembled and used to measure thread pitch in tight or enclosed spaces. Nut and Bolt Size Guide Storage Box: Our size organizer box features clear nut and bolt labels for quick and easy identification of nuts and bolts. Sticker styles random, Not accepting designation Material: aluminum Color as shown Package Contents: 44pcs nut and bolt 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.