70 mm 4 Jaws Self Centering Chuck with Back Plate & Fixing- Suitable to Mount on 3" (75 mm) & 4" (100 mm) Rotary Table -4 Slots Tables.*Overall height of this assembly is around 52- 53 mm. so you can decide accordingly considering you milling machine size when you think of buying it to mount on your existing Rotary Table. It is supplied with a Mounting Back plate, a set of T-nuts apart to ensure easy and quick Mounting on the Rotary Table.High * Designed to fit our 3 or 4" Rotary table with either 3 or 4 slots. The chuck mounting is standard Unimat Thread M14 x 1 * The Back plate has been made of mild steel.