0300 in, Clamping Range 3/16 in to 1-1/4 in, Features 140 Percent More Bearing Surface than Competitor Milling Chucks;For Quiet and Stable Heavy Milling;Nikken Patented Design;Nut Body Contact, Nose Clamping and Anti-Vibration Mechanism;Thick Body and Internal Slots Provide Extremely Strong Chucking Torque and Rigidity.