1. DURABLE METAL MATERIAL: All-metal Keyless Chuck, three-claw and spring are heat treated at high temperatures for durability 2. SIMPLE TO USE: Chuck allows quick and easy accessory changes without changing collets 3. WIDE RANGE OF APPLICATIONS:Applicable to FOR 9/32-40 thread, inner hole direct 6.2mm model is 4000, 400,3000, 398, 395, 300, 285, 275, 200, 100, 8200, 800, 780 , 770, 7700, 750 4. NOTE:8050-N/18 can not be used, the thread can be matched, but the machine shaft is too short. Category: Electric grinder chuck Full length: 23.4mm Tooth width: tooth distance 0.75mm Clampable range: 0.4-3.2mm Chuck range: 0.4-3.4mm Length: 2.1cm, Diameter: 1.4cm Material:steel colour:black Package Contents: 4 x Keyless Chuck Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.