This Grade R twin-line welding hose carries oxygen through the green line and acetylene through the red line. Made from synthetic rubber with an oil-resistant cover, it has a 3/8-inch I.D., BB fittings, and a 50-foot length. It is rated for up to 200 psi and operating temperatures from -40°F to 212°F. California Proposition 65 warning: This product can expose you to lead, a chemical known to the State of California to cause cancer and birth defects or other reproductive harm.