The Repairer looks like a level 15 tank with a screwdriver end and a container full of screws on the back of it. The amount of screws varies depending on how much Exp you gain after upgrading to the Repairer.
The Repairer repairs damaged turrets made by the Engineer. It starts out with five screws in its container. The Repairer uses one screw per repair, and a screw can be gained every 50 Exp earned. The Repairer can be easily defeated by any Smasher class tanks, as the Repairer cannot attack it.