I have an old set of 2/0 weld cables and they both have an inline connector that I have never seen before, hoping someone can identify? Problem is that they have no name on them. Each side has four "fingers" that i assume are supposed to grab and engage with the fingers on the mating connector. The fingers are about 2" long and there is a rubber boot that covers the fingers that slightly accordions in when it touches the opposing boot when the connectors are pushed together.

I assume that these are now obsolete, but wondering if they are OK to use. Any ideas?