The Shock Collar is a golden collar that, when worn by a victim, will shock them when a button is pressed on a corresponding remote controller.
When Knuckles the Echidna confronted Ms Alpha and her minions in order to kick them off of the Floating Island, Mr Gamma placed the Shock Collar on Knuckles. Before he could react, Ms Alpha activated it and shocked Knuckles to the point that he collapsed.
Though Knuckles managed to get back up, Ms Alpha threatened to zap him again if he were to follow them. However, Porker Lewis would arrive in one of the Floating Island's Guardian Robots, and scared off the criminals. Knuckles then requested for Porker to remove the collar.