Stay safe with Dometic LP Gas Detectors. It's designed for the RV environment, the sensor alerts you to low concentrations of LP gas using its red and green LEDs. If gas exceeds 2,000 ppm, a loud, piercing alarm will sound. CSA listed. Adapter mount ring allows detector to fit a 3-7/8 in. x 3-1/8 in. cutout from a flush mount LP detector.