... Diametric.8. Many characters for optional, as more than 200 types English characters.9. It can mark different characters ... ,gear,pump,valve,fastening pieces,cylinder and various hardware. mini pneumatic marking machine Technical Parameters :Marking Range30*145 mm ... ,character size covers 2-80mm,even bigger Impact frequency 200—400HZHardness of work-pieceHRC≤60Repeat Precision±0.01mmPower Supply180V- ...