The M-20 SD is a feature-loaded ergonomic and Double/single-action rimfire pistol. It sports a machined aluminum slide allowing for use of both high velocity and standard velocity ammunition. Features include slide serrations front and rear hammer de-cocker textured grip and slide-mounted safety. These features combine to make for a smooth and enjoyable shooting experience. The SD model gets the addition of a threaded barrel for the attachment of muzzle devices. Hello Suppressors. Hello compensators. - SPECIFICATIONS: - Barrel length: 4.75 - Overall Length: 7.8 - Threaded barrel - Trigger Pull: 4lbs - Manual Safety - Overall weight: 1.4 lbs - Double Action / Single Action - Hammer Decocker - CNC machined Aluminum slide