A2B2E2K2HgNO CO 20 P3 R D is a combination filter from Drager Safety. It’s designed to protect against a wide range of gases including nitrous gases, mercury vapour and carbon monoxide. It also filters out dust and particulates. This particular filter can only be used in conjunction with full face masks as the weight is more than 300g. NO and CO filters are one time use only and must be disposed after use (according to local regulations). Hg filters can only be used for a maximum of 50 hours according to EN 14387.Due to the wide range of protection available the filters can be used in many different applications. This may include shipbuilding, metal processing or public utility services. Aluminium housing ensures filters are easily recognisable and are safe from potential damage. Shelf life on the combination filters is 6 years (from date of production).