Aussie Made Durable Hydrometers And Carboys

[pyrosx]

They are designed to be splash proof (ie liquids should find it hard but not impossible to get into the cube)

Sounds like a good design to me. Have two as fermentors, stack them on top of each other, and they vent as per normal air-lock. I guess you don't get the reassuring bloop-bloop though...

To me, those sound like a poor, and more expensive, substitute for a piece of glad wrap and an elastic band.

To the person that mentioned having "issues" with said method: you're doing it wrong.