The Smith Wesson 637 is a small-frame five-shot revolver. It features an aluminum alloy frame stainless steel cylinder and barrel and three styles of external hammer. This pistol also offers integral front and fixed rear sights black synthetic grips and rating for continuous P use. The Enhanced Action model sports custom wood grips. The older Smith Wesson 637 has a black blade front sight and full-length extractor.DetailsAction SADA - Caliber 38 Special - Capacity 5 - Barrel Length 1.875 - Finish Matte Silver - Sights Fixed - Frame Alloy - Grips Basketweave Wood - Overall Length 6.31 - Weight 15 oz. - Performance Center by Smith Wesson - Where fit meets performance. From hand-cutting and fitting to precise fine-tuning Performance Center firearms are top performers. Originating from standard designs or created from the ground up Performance Center revolvers hunting revolvers pistols and modern sporting rifles are the ultimate expression of old-world craftsmanship and modern technology.