30L standard plastic screw top fermenter.
Never was able to get a proper seal, even when wetting the rubber inlay with a bit of iodophor solution. The S airlock that came with it, is also ****.. if you look at the manufacturing, and how the 2 sides are pressed together, you'll see about a 2mm plastic strip or bump running all the way up both sides that inhibit a snug join with the small rubber bung in lid. To airlock properly, you'll want to sand it smooth or trim with razor blade or just buy a quality 3 piece airlock to begin with.
And let's not forget how hard those lids are to remove if over-tightened or how many posts I've seen here on AHB where users of said fermenters are asking why they have no action in airlock, 3 days after pitching, is my beer ok sort of threads.
Bloody useless.
Hey, but at least if you drop one of those bastards full of beer it'll only bounce and maybe get your pants a little wet whereas if you drop a full glass carboy... well, i won't go into that :unsure: :blink: