GearWrench Three-Way Battery Tool The GearWrench Three-Way Battery Tool features sharp steel blades that remove corrosion and put a correct angle on terminal clamps and posts, and the 6 blade tapered reamer can quickly clean terminal clamps. The post cleaners on the GearWrench Three-Way Battery Tool are marked positive and negative, and are sized to accurately fit terminal posts and cut the correct angle, proper cleaning of terminals and posts will ensure perfect contact.