The Smith & Wesson 4566 is a single-stack "Third Generation" S&W auto pistol chambered in .45 ACP. Along with the larger Smith & Wesson 4506, its "big brother", it is one of several .45 ACP pistols authorized by the LAPD. It is also available in the "tactical" version (equipped with an accessory rail). It can be considered the S&W 45 auto equivalent of the Colt Commander.