Double-head Jewelry Pneumatic Engraving Machine The pneumatic graver tools feature 400-8000 strokes per minute, flexible, convenient & efficient, and can adjust the machine's speed. A throttle bias adjustment valve for tailoring throttle response, and a dual- stage precision air regulator. Advanced ergonomics include front air pressure adjustment, the advanced valve pulse unit with virtually no noise or vibration. Characteristic: Technical Parameter Precise & Adjustable Gauge Ergonomic Design Easy-To-Operate Panel Model: JH-G01 Power Supply: 220V 50Hz Adjustable Speed: 400-8000 rpm Adjustable Pressure Range: 0-4 kg Product Size: 13 x 29 x 24cm/ 5.1 x 11.4 x 9.4 inch Package Content: 1 x Jewellery Engraver Machine 1 x Foot Pedal 1 x Filter 2 x Pneumatic Graver Handpieces 1 x Connecting Pipe 1 x English Manual