Invensys Building Systems' new Erie general close-off (AG) actuators now fit in baseboard systems. Measuring 2-3/8" 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" wide. It is UL-listed and uses a proven manual override design. The patented PopTop Spring Return Modulating actuator is now UL-873 listed on both the SR and NSR modulating actuators. The new actuators are direct replacements for all existing Erie PopTop 2-Position actuators or PopTop Modulating actuators of like types. Invensys Building Controls. Circle 5.