Heavy Duty 3mm Airline – BLACK Dreamworks Heavy Duty airline 3mm. Tested to 160psi this airline offers longer life and greater reliability; resists abrasion and chaffing. Will not slip off cylinder nipples or Tee fittings. Without question, the highest quality airline we could offer. Sold in 12′ lengths. Tubing Specifications:     Color: Black     Outside Diameter: 3mm     Inside Diameter: 1.8mm      12 Feet