Superchuck Ball Bearing Chuck, K4 Key, 1 8 in to 3 4 in Capacity, 4JT Short Mount no checkout provides full sock construction for provides full sock construction for unmatched comfort and insulation 100% Kevlar™ thread for maximum seam strength Fully welted seams and self hemmed cuff for extended life and safety or inactive fillers Aerosol provides a pinpoint stream with foaming action Ball bearing construction maximizes gripping force and drilling accuracy Jaws center ground for straightness and alignment One piece sleeve eliminates crack between driving teeth often found in other designs Through hardened sleeve teeth plus hardened nose and keyholes provide outstanding wear resistance Fluted sleeve standard