it works fine and two disc are supplied on for .325 chains and the other for is for pico chains, see STHIL . It is accurate and if you take your time , is better than hand filing, not any day, but every day. I was hand filing for years, but i could never get it to what a grinder can do. Therefore, of you cut a lot, this makes a great buy , and its a copy of a well known brand, but HALF THE PRICE, UPDATE, THIS A PRO TOOL