Diameter : 4mm.Suitable for: Chainsaw chain in 3/8inch P. Convenient accessory for quickly sharpening teeth and depth gauges in one operation. Built-in file tolerance compensation. Small size allows you to carry the electric chainsaw sharpener with you everywhere, with a plug-in design, so you don't have to worry about the chainsaw sharpener not working, you can neatly sharpen the chainsaw chain, it's a chain useful saws parts and accessories. You can use an electric chain sharpener to keep your chain in top condition by sharpening your chain without removing it, and save money with an automatic chainsaw tool. Made of durable plastic and whetstone. Extra whetstones are provided for replacement. Please note that the grinding wheel is very wear-resistant and does not need to be replaced frequently. Keeping the chain and guide rods oiled reduces friction and helps extend product life. This chainsaw sharpener is lightweight and portable, and the chainsaw sharpener is easy to use outdoors. The new electric saw sharpener offers a quick and easy way to sharpen saw chains. Package Size: 38 x 6 x 2.5 cm Product size: 32*6*2.5cm Delivery quantity: One piece