Do you have some info on those caps are they for AC or DC and what voltage / Current rating are they?
Definitely AC. Current ratings look to be plenty, at least 10A I'd guess. And probably a voltage rating big enough to handle AC line voltages. (Otherwise I wouldn't have bought them.)
For those who aren't familiar with these devices, here's what I know: Feed-thru caps are a 3-terminal device, with the capacitor going to ground (which is the body of the capacitor that bolts to a ground chassis. Otherwise they're essentially a conductor to pass the current into and out of a chassis. They're used in EMI filters, so one scenario is that you have a line filter (typically with both common mode and conventional filtering) in a subchassis, and you pass the current in and out of the subchassis via the feed-thru caps. I think they're more common in high-frequency EMI environments, but worth considering for DIY audiophile applications.