KING-GAGE compressed air filter car­tridges are available in different grades. Recommended options are listed below. Our Ultra-C and Type 750/800 cartridges meet the particulate require­­ments of ISO 8573-1 (ISO 8573-1:2010 specifies purity classes of compressed air with respect to particles, water and oil independent of the location in the compressed air system at which the air is specified or measured. ISO Class noted is for particulate removal only.) Quality Class 1 spec­ification for compressed air. Type 300/300 cartridge sets provide lower pressure drop in app­lications and meet ISO 8573-1 Quality Class 3 specification for partic­ulate removal.