At least one of the robots was available on the Enterprise-class refit of the Constitution-class heavy cruisers in a fully-equipped gymnasium on the bottom deck of the secondary hull. The gym had a boxing ring with a mechanical sparring partner.
The robot was about six feet tall, metallic, flexible and mobile, with four long, tentacled legs attacked to a spherical base. Two shorter arms were attached to each side of a pivoting torso section at shoulder points. Each appendage ended in a three-pronged grappler. It had a metal globe for a head that resembled the compound eyes of an insect. The robot was capable of sparring in boxing and other modes, as its limbs responded to judo and other combative movement. Each arm was strong enough to knock a person clear across a room.
The USS Icarus was assigned to an exploratory mission outside the galaxy in the year 2274. It was to be piloted by a crew of noncorporeal Phaetonians with Janice Rand as their only human liaison. But contact with the Galactic barrier drove the Phaetonians mad, and the USS Enterprise beamed over a rescue party. Considering the Starfleet officers invaders, the Phaetonians weaponized various aspects of the ship tin their defense. They derailed a turbolift, forcing the rescuers into a gym. The mechanical sparring partner attacked Hikaru Sulu, throwing him across a room. When Sulu fell, his head hit the leg of some gym equipment, requiring medical treatment by Leonard McCoy aboard the Enterprise’s sickbay. (TOS comic: "Eclipse of Reason")