I bought this to allow me to dismantle and service the old-fashioned cup-and-cone (aka Ashtabula) bottom brackets on my wife's and daughter's bikes. The tool is 15cm long from pins to the end of the handle, the pins are about 3mm diameter and the hinged jaw means the pins can be anything from 1cm to 6cm apart, so you could use it for other two-pin applications (eg angle grinder locknuts or those self-extracting bottom bracket bolts).
It's a bit flimsy, to be honest, and to reverse the direction (ie from loosen to tighten) you have to unscrew the pins and re-insert them from the other side (the pivoting jaw only stays closed if you're pulling away from that side - not pushing towards it).
It did the job, but you wouldn't want to have to use it all the time. Of course, if you're using it to service old fashioned stainless steel bottom brackets, then you're unlikely to use more than a couple of times a year anyway, in which case it should be fine for a while.