The Model 637 Airweight blends an aluminum alloy frame with a stainless steel barrel and cylinder. At under 15 ounces it is one of the lightest centerfire revolvers available, making all-day carry genuinely comfortable. Type: Revolver Action: DA/SA Caliber: .38 Spl +P Capacity: 5 Year introduced: 1996, USA Weight: 15 oz Overall length: 6.3" Status: Active Intended use: Carry, Backup