... national patents, includes: Patent of practicality new type 012101210661.5, patent of outside design 01 3 10638 ... engraving whatever plane or bend surface, No noise, No smell, No dust, and you can use it ... strong power, high speed, lower stress, and top quality. It suit for industries of board patternmaking ... plating, odd metal plating, alloy plating, special type plating, etc. it not only for hanging ...