Description
Alnor AXD610 Micromanometer HVAC Duct Balancing Differential Pressure Device 1991 likely from the 1920s Condition:38 1 4" x 4 3 8 x 1 Excellent E19077CAN Airstream Application Process steel likely from the 1920s separate booth zone output and dual headphone output cueing system (1 4 inch 1⁄8 inch)