The Smith & Wesson M945 is a single-action, .45 caliber semiautomatic pistol from Smith & Wesson. It is built primarily on the S&W 4506, but incorporates design features from the M1911 pistol series, such as a SA-only trigger, a grip safety, and a frame-mounted thumb safety. The M945 can be distinguished from a M1911 by the unique contours on the slide and by the internal safety mechanism inside the slide, which is externally visible as a black circle where the s&W 4506's safety switch would be located. None of the parts nore the magazines from M1911s are compatible with the M945.
