Suitable Size: It includes 6 different ranges (8-12.7mm, 12.7-19mm, 19-32mm, 32-54mm, 54-90mm, 90-150mm) for your choice High quality inner diameter gauge: The surface of the product is nickel-plated, with long service life and bright surface, The arc of the measuring head is good Non-slip handle: The handle has a diamond grid, which makes measuring more convenient Soft and constant spring tension: Constant spring tension provides uniform contact pressure