The Shwartz rings were capable of generating lightsaber like weapons to use for fighting. Spaceballs showed them used as both swords and beams. Users of the upside had yellow blades while users of the downside had green ones.
The first ring shown in the movie belongs to Dark Helmet, and resembles a snake with a jewel in its mouth. The second belonged to Yogurt, and had a capital S written in gems. Lone Starr practices using this ring by lifting up a giant statue of Yogurt. Yogurt allows him to keep the ring.
Lone Starr uses his new Schwartz-ring to save Planet Druidia from losing all its air, by switching Mega Maid's vacuum cleaner from "suck" to "blow". He then engages in a duel with Dark Helmet, creating a blade as big as his. Dark Helmet tries to give himself an advantage by tricking Lone Starr into giving him his ring. However, Yogurt boosts Lone Starr's confidence by admitting that the ring is nothing more than the prize from a Cracker Jack box, and that Lone Starr has the real Schwartz inside him. Lone Starr proceeds to overcome Dark Helmet in the fight.
Due to a technical goof, the Schwartz-ring reappears on Lone Starr's finger after he and the other heroes successfully escape Spaceball I.