Features 1.pull down the security board open the grinding chain utensil, 2. fix the chain to the position shown by the chainsaw sharpener rivet according to your chainsaw style. 3. after fixing the chain, close the outer casing of the chain cutter.push the security board onto the fixing rivet exposed part. 4.put the bottom of the chainsaw sharpener on the ground and start the chainsaw to make the grinding stone contact with the running chain to achieve the working effect. 5. tips:in order to protect your chain, and because the main material of the chainsaw sharpener outer casing is plastic, with is easy to wear and tear. Specification Material: ABS Color: Yellow Size: 22 x 14 x 4 cm Weight: 350 g Package Include: 1x Woodworking Chain Saw Grinding Tools