13W3 adapters

Hi, I need to make a 13W3 "extension cord" -- M-F *not* the M-M (or F-F, depending on how you look at it!) cables that Sun offered. I salvaged a sufficiently long video cable off of a <mumblemumble> Sun monitor -- so that gives me *one* end (and, one *sex*). The *other* sex is a bit more elusive (i.e. the gender that is present *on* the actual CPU). But, I found a <random> 13W3<->3BNC adapter in one of my goodie boxes. The 13W3 connector is "just right" (sex, form factor, mounting, etc.). So, the issue (and hence the question!) is: what sort of device might *want* this adapter (i.e. why should I *keep* it and not just salvage parts from it)? Note that the BNC pigtails are only a few inches long so I assume this would be attached to a 3BNC monitor and a "regular" Sun cable used to tether that to the CPU. Thanks! --don