Function: 1. Do sharpening: The fine and even coating provides excellent sharpening results for the chainsaw, extending its lifespan. 2. A total of 30 pieces: including 3 types of drill bit, 4.0mm, 4.8mm and 5.5mm, and each type ma 10 pieces, so there are 30 pieces. 3. Flexible work: It also allows for wide application in polishing wood, molds, steel and many other metal materials. 4. Great material: using high quality emery material that does not deform, ma also good durability for long working hours. 5. Easy to install: Lightweight and compact, the 3mm shank grinding file ensures quick and easy installation. Specification: Item Type: do Chainsaw Sharpener Material: Emerald Handle diameter: approx. 3mm / 0.12 inch Suitable tools: do electric grinder, electric drill and other electrical tools. 4mm/0,16 inch (approximately) grinding head: suitable do electric chainsaw, do 3/8 chain. Grinding head 4,8 mm / 0,19 inch (approximately): suitable do small chainsaw, do chain 325 and large chain 3/8. Grinding head 5,5 mm / 0,22 inch (approximately): suitable do large chainsaw, do chain 404. List of packages: 30 x Sharpener do chainsaws