Product Description These handy 12 volt chainsaw grinders offers an economical way to sharpen your saw chain accurately and quickly. Simply connece the clips to a standard 12 volt auto-type battery to power the unit and your ready to go. The unit Includes 3 sizes of sharpening stones: 5/32, 3/16 & 7/32 and replacement stones are readily available and inexpensive. A must have tool for sharpening your chaonsaws in the field. JAKMAX precision parts are the experts in chainsaw and mower accessories and this little ripper is a real must have tool Features & Specs : JakMax full warranty comes with 3 stones 12Volt 20,000 rpm TOOL KING are an Authorized JAKMAX distributor