Professional tool for commercial or occasional use. Suitable for repairing sump / gearbox and differential drain plug threads. Suitable for use on cars / vans / motorbikes etc... Used to tap the damaged thread slightly oversize then fit a new drain plug and washer (supplied in kit). Eliminates the need for a new sump. This kit will re thread a M12 threaded sump to M13. SET Includes; Includes six M20 sump plugs and two sets of washers. 1 x tap for re threading M13 6 x oil drain plugs 6 x washers SIMPLE TO USE Disassemble the damaged oil drain screw Choose a tap, (if the original hole is M12 then it needs to be an M13 tap) Use a tool operating the tap to enlarge the diameter of oil drain hole Take a washer through the new oil drain plug and then insert a new oil drain plug. Comes in a handy case for easy storage and transportation.