The new General close-off (AG) actuators fromErienow fit in baseboard systems. Measuring 2 3/8 inches wide, this patented, UL-listed actuator has improved close-off ratings and is designed to fit in virtually any style of heating unit. The High close-off (AH) actuators are new. For ease of installation, this actuator is now 2 5/8 inches wide. It is UL listed and uses a proven manual override design.