Reciprocating Pneumatic Ultrasound Grinder 1/8" (3mm) Micro Air Pencil Die Grinder Kit - Professional Polishing & Engraving Tool for Metal, Wood, Jewelry Making & DIY Crafts

Nicely made and finished. The black anodized aluminium handle is somewhat wider than the other makes with a straight tubular handle. At the chuck end it is comfortable on your fingers when doing fine work.After using for less than 5 minutes, the air tube blew off where attached to the handle end. There was no way to fix this with the little tube fitting provided. Fortunately, the male brass threads on the handle end are 1/4"-28. I found a replacement bushing adapter with 1/4-28 female and 1/8" NPT male threads. On to that I attached a Push-to-Connect adaptor with 1/8 NPT female and 5/16" for the hose. The hose provided is 8mm-5/16" OD.If you do not have an oil bowl on your air regulator, use an eye dropper to manually add about seven drops into the quick disconnect end throughout the day. After oiling restart at slowest speed so that the oil may flow through the handle.