M.MH-120 Micro Grinder Handpiece has a geared 3-jaw #0 chuck that takes any size rotary accessory or drill bit with shanks up to 5/32? (4mm) diameter. If you already have a Foredom K.1070, K.1080, or K.1090 Micromotor Kit the H.MH-120 Micro Grinder Handpiece will work with the HP4-917 Control Box and HP4-960 Foot Control in those kits. Handpiece Specs: Length= 8-3/32? / 205.8mm, Weight= 1-lb. 2-0z. / 510 grams, Diameter= 1-1/64? / 26mm at chuck end. HP4-917 Control Unit has switches for On/Off Power, Forward/Reverse Rotation, and Manual/Foot Speed Control selection. Overload Protection turns on a red light and sounds a beeping alarm if the motor ever stalls. The Control Box Back has a voltage selector switch that lets you choose from 110/120 or 220/240 volt and receptacles for the Variable Speed Foot Control or Optional On/Off Foot Switch. This is the same control unit that comes in Micromotor Kits K.1070, K.1080 and K.1090. Features: 20,000 RPM Max Speed High torque (9.24 oz.-in.), 60/50 Hz, 4.82 Amps DC Dial Control and Foot Control for variable speed Forward or Reverse rotation Built in overload protection CE compliant Two Year Limited Warranty Kit Includes: Control Unit, Handpiece, Variable Speed Foot Control, Handpiece Cradle, Chuck key with handle, and extra set of motor brushes. HP4-927 Optional On/Off Foot Switch- This control is available separately and does not come in the kit. It plugs into the back of the control box and allows you to turn the motor on and off without changing the speed set by the dial. 1. Overview of Foredom’s Micromotor Kits with Motor Brushes – the K.1070 High Speed Rotary, K.1020 Chuck Style-High Torque, and K.1080 Hammer Micromotor Kits. Owner’s Manual for K.1020 Chuck Type Micromotor Parts List for H.MH-120 Micromotor Handpiece Overview of Foredom’s K.1070, K.1020, K.1080 and K.1090 Micromotor Kits. These “Brush Type” kits utilize the same control box. Video identifies unique and shared kit components.