One of approximately 900 manufactured and registered with the BATFE in the early 1980s, these S.W.D. Inc. Auto Connectors were, and still are, one of the most cost effective ways to make an AR-15 platform rifle fully automatic. Fully marked on the main body, the "Lightning Link" consists of a main body that hooks around the disconnector and a vertical arm that extends upward into the bolt raceway; if properly configured, the back end of a semi-automatic pattern bolt carrier will strike the arm, pulling back the main body and disengaging the disconnector, emulating the function of a factory auto sear but without needing a full auto pattern bolt. This example comes with two arms, one measuring about .032" and the other about .050" in thickness; info from the consignor indicates that the .050" arm was fabricated for best fit with the host gun Item B.

Manufactured in Geneseo, Illinois as a conventional AR-15 pattern, the addition of an Ares Industries Shrike 5.56 upper receiver has converted this item to a piston driven belt-fed "squad automatic weapon" style rifle. The upper has an A2 flash hider on the heavyweight quick-detach barrel, post front sight on the gas block, ventilated round handguard with plastic heat shield and a mounting rail at the 6-o'clock position, and a flip up top cover with an Elcan M145 optical sight with Killflash glare eliminator on the top rail. The lower receiver bears the standard Armalite markings on the left side, with a right handed "SAFE" and "FIRE" selector setup, checkered pistol grip, and a MagPul MOE fixed buttstock. Internally, the main components are standard, with minor adjustments made to the bolt carrier and rear leg to accommodate the Link. A large number of accessories are included, with sections of disintegrating links, a plastic belt carrier with a magazine-shaped adapter, bipod, carry handle, extra Shrike bolt carrier (note: "full auto" body, not compatible with Link), and an extra A4 pattern upper receiver. The extra upper has an A2 flash hider on a 16inch heavy barrel, Magpul MOE handguard, Bushnell ACOG-style optical sight, and a Fail Zero brand bolt carrier, which also appears modified for compatibility with the Link.