On a variety of vehicles, mostly emergency ones but also motor homes and RVs, I've seen two external battery posts, each about 1" in diameter and 4" long, mounted about 4" apart, near the front or rear bumpers (sometimes elsewhere). One is covered with a black rubber sleeve, and the other with a red rubber sleeve. Both can be removed easily for attaching jumper cables to provide (or receive) assistance to (from) another vehicle. Internally these posts are connected to the battery.
Where can these be purchased? I've tried all the auto parts chains, NAPA, RV dealers, and various truck stops. Everyone seems to know what I want, but has no idea where they are sold. Any ideas?
Thanks.