Often misidentified as hammerless, the Centennial is the designation for the frame-concealing encloses-hammer Smith and Wesson snubs. Introduced in 1952 as the Model 40 and named in honor of the company’s centennial the Centennial features a unique “Quasimodo” style humped back frame and back strap. This frame shape completely encloses and conceals an internal hammer that employs a double action only trigger system. Combined these features prevent the snub from either snagging during a draw or being thumb cocked prior to firing. The Centennial is very popular with many shooters as its unique frame shape permits the shooter to move his hand up high on the back strap and aid in recoil control. The classic Centennial and some reissued versions feature a grip safety on the back strap that must be depressed in order to fire the snub. Models include the Model 40 (blue steel frame), Model 42 aluminum-alloy frame) both with a grip safety, Model 640 (stainless steel), Model 442 (blue steel cylinder with an aluminum-alloy frame), and the Model 642 (stainless steel cylinder with an aluminum-alloy frame). New Centennials have frame cutouts that will not accept many commonly available J-frame sized stocks.