The RYOBI Sharpening Rotary Kit allows you to easily sharpen chainsaw and lawn mower blades. The Chainsaw Sharpening Guide features 30 degree and 60 degree guidelines for optimal angles when grinding along various chains. The Lawn Mower Blade Sharpening Guide provides a 30 degree angle for optimal blade sharpening and both guides are compatible with standard rotary tools. The kit includes (1) Chainsaw Sharpening Guide, (1) Lawn Mower Blade Sharpening Guide, (1) 3/8 in. cylinder grinding stone, (1) 7/32 in. chainsaw grinding stone, (1) 5/32 in. chainsaw grinding stone, and (1) 3/16 in. chainsaw grinding stone.