The Bullard COHP Carbon Monoxide (CO) Monitor provides continuous monitoring of compressed breathing air to help ensure OSHA Grade D breathing air compliance for supplied-air respirator systems. Designed for rugged industrial environments, the COHP continuously measures carbon monoxide levels and features highly visible LED status lights plus a loud 90 dB audible alarm when CO levels exceed preset limits. The durable polycarbonate housing can be used as a portable unit or mounted to a wall, while operation on either 110/220V AC power or battery backup provides reliable protection in the field or shop. Compatible with Bullard supplied-air respirator systems, the COHP is an essential safety device for sandblasting, painting, welding, and other industrial applications where clean breathing air is critical. EQUIVALENT to the RPB GX4