Those sound like "B-Caps" made my Magenta. I've never used them, but I don't think they come vented. I just use peanut butter and baby food jars, and I vent them myself. You could always vent the B-caps the same way - drill a tiny hole and seal it with a double layer of sterile spots.
Hi Royal,
I'm unfamiliar with the sterile spots you mentioned...what do they look like and where can I find them?