Features： 1、For Sharpening: The fine and even coating enables sharpening effects on the chainsaw to prolong the service life. 2、30Pcs in Total: Including 3 kinds of the grinding bit, 4.0mm, 4.8mm and 5.5mm, and each type has 10pcs, so there are 30pcs. 3、Flexible Works: Also allows for extensive application in the polishing of wood, mould, steel and many other metal materials. 4、Great Material: Using high quality emery material, not likely to deform, has good durability for long hour working as well. 5、Easy to Install: Light in weight and compact in size, the grinder file with 3mm shank ensures quick and easy installation. Specification： Item Type: Chainsaw Sharpener Material: Emery Shank Diameter: Approx. 3mm / 0.12in Applicable Tools: For electric grinder, electric drill and other electric tools. 4mm / 0.16in (approx.) Grinding Head: Suitable for electric chainsaw, for 3/8 chain. 4.8mm / 0.19in (approx.) Grinding Head: Suitable for small chainsaw, for 325 chain and large 3/8 chain. 5.5mm / 0.22in (approx.) Grinding Head: Suitable for large chainsaw, for 404 chain. Package List： 30 x Chainsaw Sharpener