Features:This multi chuck allows you to quickly and easily change accessories for your Dremel multitool without using collets. It accepts accessories from 0.5mm to 3.2mm shankCorded rotary tools without changing colletsIt accepts all accessory bits with 1/32 and 1/8 shanksEliminates need to change collets when swapping between bit sizesTwist-to-tighten/ loosen with heavily-knurled grip means no wrench or key neededHeat treated & tempered high-carbon steel for durability， rust-resistant black oxide finishCapacity: 0.5 to 3.2mmChuck Specifications: 7x0.75mmSize: Approx. 2.2x1.3cm/ 0.86x0.5"Instructions:1. Output shaft is 3.9mm diameter of the 7x0.75 specifications between electric grinder and soft pumping2. If between the head portion of the housing and the output shaft is hollow， the output shaft projecting out over the length must than 10mm3. If between the head portion of the housing and the output shaft is nearly solid， the output shaft projecting out over the length must than 13mm4. The hollow portion between soft shaft handle and output shaft， must more than 13.8mmPackage Included:1 x Multi Chuck Keyless