GBR25-R Differential Pressure Gauge and Alarm $125.00 Vapor Intrusion and Radon System Alarm and Gauge Measures pressures up to 40″ w.c. Audible and visual alarm with adjustable set point Plug and play operation* Built-in alarm silence switch Includes power supply and length of vacuum tubing for connection to riser pipe Includes wiring for a second programmable relay Add to cart