The B&T SPC45 PDW SD is a compact, purpose-built .45 ACP firearm designed for both tactical and personal defense applications. It features a 4.5-inch barrel with a 1:16 twist rate and a polymer lower with aluminum upper, making it lightweight yet durable. Instead of a standard threaded barrel, it uses a B&T-specific tri-lug muzzle attachment, allowing quick installation of suppressors designed for the system or adapters to standard threads. The firearm comes with a 25-round B&T metal magazine, ambidextrous controls, and backup folding sights, although it does not come optics-ready or with factory night sights. Its hydraulic-assisted blowback system reduces recoil, and the endcap / PDW stock design makes it compact and maneuverable, while the overall package is well-suited for suppressed shooting or close-quarters scenarios.