Features Durable Material:Made of stainless steel, this radius gauge is durable and rust-resistant. All radius gauges are made of high-quality steel, heat-treated and chrome-plated, with high strength, good resilience and beautiful appearance. Easy to Use: The radius gauge has two types of blades, and each blade is clearly marked for easy identification of the blade you need. So it can check convex and concave. Convex patterns are used to detect concave arcs, and concave templates are used to detect convex arcs. Superior Design: 360 degree locking screw design allows you to unfold or fold easily. There are four different shapes and sizes of radium meters to meet your every need. Accurate Measurement: Each leaf is clearly marked for easy identification of the leaf you need. They measure accurately with little error and will help you check tool radii quickly and easily. Multipurpose: A very useful gauge widely used by tool and die makers, machinists and many other workers to check tool radius. Features: 1.Made of stainless steel, this radius gauge is durable and resistant to rust. 2.This radius gauge has two types of leaves so it can check both convex and concave surfaces. 3.Each leaf is clearly marked, convenient to identify which leaf you need. 4.There are four radium gauges in different shapes and sizes to meet you various need. 5.Very useful gauge for tool & die makers, machinists, and many other worker to check the radius of tools. Specification: Material: Stainless steel Measuring Range: R0.3-1.5/ R1-6.5/ R7-14.5/ R15-25 Weight: 270g / 9.5oz(approx.) Package list: 4 * Radius Gauges Package List