Cartridge for MAKO PD-1803 or LAWRENCE FACTOR X65247. This industry standard 27" cartridge has a "MAKO" style connection which is used in many purification systems. Our AIM-247 contains the highest quality molecular sieve 13X and activated carbon along with a catylist for carbon monoxide (CO) removal, all in a single cartridge. This filter cartridge is housed in a clear tube with a blue indicator strip allowing the user to monitor the level of saturation.