It is the buckle end (only) of an
equalizer girth, often used for polo saddles. Note how in the attached image the large solid D rings pass through the layers of the straps. The only way I can imagine these are made is that the straps are sewn ONTO the D rings. Solid welded D rings. My straps are intact, all stitching is intact. Where did the D ring go? I don't know, I got the straps, attached to the saddle, just as you see them. No girth, only these equalizer straps.
As for junk slappers, and bondage gear... definitely yes. For those of you who say otherwise, I suggest you merely lack imagination. Or courage.
