Features 18 PIECES IN 1 SET: Including 18 pieces of emery grinding heads with size of 4.0mm, 4.8mm and 5.5mm, sufficient quantity to meet different grinding needs. DURABLE MATERIAL: The emery particles are finely and evenly polished, hard and wear-resistant, the titanium-coated surface increases corrosion resistance. EASY TO INSTALL: These grinding heads have a 3mm diameter shaft and can be mounted on power tools such as electric grinders, drills, etc. APPLICABLE CHAIN: 4.0mm drill bit is suitable for chainsaws with 3/8 chain, 4.8mm drill bit for 325 chain and large 3/8 chain, 5.5mm drill bit for large chainsaws -404 chain. MAIN PURPOSES: These grinding heads are widely used for polishing and grinding metal, chains and wood etc. and are efficient and durable. Specification: Item Type: Grinding Wheel Set Material: emery Shaft Diameter: Approx. 3mm/0.12 inch Applicable tools: Electric grinder, electric drill and other power tools 4.0 mm grinding head: suitable for chainsaw, for 3/8 chain 4.8mm grinding head: Suitable for small chainsaws, for 325 chain, large 3/8 chain 5.5mm grinding head: Suitable for large chainsaws, for 404 chain Package list: 18 x Grinding Head Package List 18 x Grinding Head