My interest in this QD was actually piqued by a different company’s sling video, where its true name was never given. I recognised it immediately as Ferro Concepts’ D Loop Heavy Duty Push Button QD Swivel 1″ and I bought one from Tactical Kit.
It’s mainly marketed on its release button: flush to the swivel body, virtually eliminating negligent release.
While a sling can be directly attached to the QD, as shown in the pic above, it’s also of use with MASH or HK style CLASH hooks – bridging between sling hook and the QD socket installed on a rifle.
My interest in it is the fact that the swivel body is really wide, which means the QD button is really wide, which means its easier for my massive hands to operate. Likewise, the D loop really gives you something to get hold of.
Here it is compared with a standard 1″ QD and it’s worth bearing in mind that Ferro’s swivel body is both wider and taller:
Secondly, while a standard ovoid loop canalises 1″ webbing and keeps it largely fixed in place laterally (a feature prized by some), Ferro’s D loop allows the sling an arc of flexibility. For me this improves how the gun hangs – a purely subjective, marginal gain, but notable nonetheless.
That benefit really comes into play when using a two point sling in one point mode, as it allows the sling to conform better to the user – here’s an image from Ferro’s site:
Because of the swivel’s D loop, larger body and button, it’s also easier to make the transition between two and one point configuration with gloved hands.