Co2 Omnibus Regulator -AQUARIUM Adjustable for co2 tank & co2 cartridge tank UP co2 regulator designed to easily connect. Simply tighten the regulator clockwise direction by hand, without the need of any tool. for 4/6mm air tube. To release simple regulator from the CO2 bottle, to be sure the valve of the bottle is close, then release remnant gas pressure from the regulator, then unscrew from the bottle. Do not unscrew the regulator before remnant gas pressure released, that cause damage of the regulator 0-rig.