Dagger Tools Radius (Profile) Surface Checker, black anodized aluminum construction. 12 radius checker points: flat, .75", 1.25", 1.5", 2", 3", 4", 6", 12", 24", 36". Ideal for checking or confirming outside radius points on panel surfaces or to aid in layout of templates, bucks,and forms. And once a suface is defined will aid you during the metal rasing or repair process, to determine have you stretched the surface enough and is it uniform. Also used for checking E wheel profiles, planishing hammer dies, bossing mallet face surfaces,and most calibration dies shapes. For metal shaping, auto body repair & restoration. 12 1/2" long X 3 1/2" wide. Must have tool!