Ajax tools makes a wide range of air hammer / zip gun chisel bits for scraping, chiseling, cutting, punch, ripping, splitting, etc. There are 2 common sizes of zip gun chisel bits .401 and .498. For each specific size there are also two types of bits Turn Type and Non-Turn Type. As you would imagine the turn type has a collet and is free to rotate while the non-turn type has 4 ball slots to keep the chisel from turning. Any air hammer can become a needle scaler with the proper ajax attachement.