Whirlpool 70 was a tracked robot built out of a swimming pool cleaning device, armed with a heavy rotating steel frame with four flailing maces attached to it, which acted as the robot's full-body spinner. According to Robot Wars Extreme: The Official Guide, the rotating frame could also be fitted with spikes or hooks in place of the maces.
Robot History
Extreme 1
W70 started the match very slowly as it tried to get its spinning body up to speed. Drillzilla rammed W70, but was pushed away by Firestorm 3. NEAT Machine used its battering ram to stop W70 from escaping, but W70 then drove very slowly away and into Sir Killalot's grasp. Meanwhile NEAT Machine had been flipped over by Firestorm 3, Firestorm 3 then proceeded to flip W70 onto its side. NEAT Machine was counted out and so was W70 shortly after. W70 was then thrown by the floor flipper. W70 then got in Firestorm and Drillzilla's way as they continued fighting. The battle ended and W70 was eliminated.