The monitors with Change feature randomly switching icons of all the playable characters in Knuckles' Chaotix on their screens.
When picking up Change, the current Combi Partner in play will be replaced with another of the playable characters in Knuckles' Chaotix. The character the Combi Partner is switched out with depends on which character's icon is on the monitor's screen when Change is picked up. Change's effect only last until the power-up's icon disappears on the bottom however, after which the original Combi Partner will return to the gameplay.
Aside of the giant crane machine at the Newtrogic High Zone, using Change is one of the only times where the player is able to get Heavy or Bomb to become his/her Combi Partner.