1 pairs 30Mpa double air-filter. 1 PCS 8mm connector. There also have the. Activated carbon filter element, if you need. The two-bucket filter cartridge is generally recommended to be filled with 360L air (about 30 bottles of 12L air). The shell is made of aviation grade aluminum alloy, resistance to high pressure. Internal use of imported activated carbon, double filtration, the air is pure and breathable. It can be used over and over again. Compatible with many kinds of air compressors.