The BW M5 Yellow Diffusion Cover is a replacement part that protects gas detection instruments. Made of durable yellow plastic, it fits securely over gas sensors to shield them from dust, moisture and other environmental factors that could compromise readings. The cover maintains response time by allowing gases to pass through while filtering out interfering substances. An essential accessory for professionals who rely on gas detection devices for work in hazardous conditions. The cover snaps easily onto compatible BW Micro 5 series instruments to support accurate, dependable measurements even in demanding environments.