Feature: Dimensions: overall outside diameter 45 mm Maximum clamping diameter: 20 mm Thread: M12 * 1 (non-standard) Hole diameter: 10 mm Uses:  Fixed solid material or hollow circle, triangle material, hexagonal material.Also with the two locking iron, jaw locking plate is used, instead of connecting rod Please note The two lock-jaw-iron insert disc 2 small holes, rotating disk locking jaw-jaw open or closed iron will, turn chuck until the jaw is pushed out, change can change the direction of jaw-jaw plate the maximum size of workpiece clamping. Note:  When installing jaw, the disk number and the number on the correspondence to claw, claw at installation should be screwed into the order of 1, 2, and note that the three-jaw disk inside the thread guide, the guide rail has a gap, the gap is screwed onto the groove edge fashion 1 1 claw claw claw 2 is screwed onto the groove edge fashion 2 feet, screwed to the slot edge fashion 3 feet 3 claws. When machining large workpieces, the need to use anti-claw claw sequence which when installed is 3,2,1. (Anti-claw can go to maximum diameter of about 45 mm ) Package included: 1pcs 45mm 3 jaw chuck 2pcs Locking lever