Oxygen Flow Gauge Regulator, 2 to 15 LPM, 3000 psi Inlet, CGA 540 Nut and NippleChrome-plated brass body with all brass high-pressure chamberInternal reseating relief valve protects against over-pressurizationSintered filter for additional safety and to extend regulator lifeSingle-Stage, Pediatric Single-Stage, and Two-Stage models available