Originally manufactured in 1985 in West Germany and imported by HK USA as a semi-automatic rifle, this item was converted into a MP5SD pattern silenced submachine Gun by C Ray Systems of Deer Park, Texas. One of the more distinctive variants of the MP5, the "schalldaempfer" used a combination of an integral silencer and ported barrel to deliver silenced, subsonic performance for special forces operators and SWAT team members; like many American commercial examples, this one retains the barrel porting but switches to a threaded mount for a detachable silencer (see Item B). Hooded post front and four-peep drum rear sights, with the "MP5SD" marking, serial number and "IF" date code on top of the receiver, caliber and HK Chantilly markings on the magazine well. The forearm and charging handle guide are properly modified for the SD's distinctive silencer, and appropriate porting has been added to the barrel. The magazine well has been modified for a proper "hinge pin" interface and functioning paddle release, with the trigger housing fitted with a right handed "S/E/F" switch and "pin" pattern selective fire trigger pack, and the bolt carrier an original factory full-auto component. Fitted with a two-position telescoping buttstock. An extra magazine is included.

11 3/4 inches in length, with red-filled maker's marks positioned to be concealed by the forearm when installed, and a knurled grip section on the exterior. Internally, the silencer has a baffle stack in the upper half, with the lower half a short section of guide tube leading to an internal expansion chamber.