MHC 638-8754 Combination Set 300mm/12", Centre head, Protractor and 12" rule, Graduation: 0.5mm and 1/32" on front face, 1mm and 1/64" on back face, Open type blades can rotate 360 degOpen type blades can rotate 360 deg Center head: To locate center of cylinder with diameter (d): 30 100mm Accuracy: 0. 15mm Protractor head: To set the blade at desired angle to an edge of a workpiece, and can be used to measure angles Range: 0 180 Accuracy: 7min. Square head: To set the blade at 90 or 45 to an edge of a workpiece Accuracy: 8min for 90 square, 10min for 45 square Blade: Range: 300mm 12", Graduation: 0. 5mm and 1 32" on front face, 1mm