Measures diameter, thread pitch & length of nuts, bolts & screws Measures fractional bolts from size 4 to 1inch up to 7inch long Measures metric bolts & screws from size 3mm to 22mm Made of very durable 1/4inch thick hard plastic Please note:the physical slightly color difference or difference, does not affect the use, please do not mind, thank you Colour:Red Material:Plastic Size:1/4inch thick x 8-3/4inch Long x 3-3/8 Wide Package Contents: 2 * bolt identification tool 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.