EQUALISER Proton - rotary machine in the form of pen for cartridges. The advanced gear system guarantees trouble-free operation and quiet operation. The housing is made of the highest quality anodized aluminum. Super low weight - only 130 grams !!! Compatible with all kinds of cartridge. Total lack of vibration! - stroke: 3.5mm - full regulation of the needle extension 0-4.5mm - engine: 5W - socket: RCA - handle diameter: 25mm - length: 11.8 cm - work range from 7 to 11V. Motor is Japan made by Mubachi.