Sensors are the heart of any gas monitors, whether 4 gas monitor, single gas, or somewhere in between. The technology packed into these little gems is quite impressive. We stock and sell a wide variety of OEM replacement sensors from BW, Honeywell, RAE Systems and RKI Instruments. Our factory trained and certified technicians are available to assist with choosing the correct sensor, or doing the installation for you in our service center. We also have other gas detector accessories that can help you with your job.