Has an automatic odour barrier instead of a water trap, so that it cannot dry out. The odour barrier can be removed for cleaning. VA-approved. - Should not be used in multi-storey buildings - The odour barrier may react to over-pressure and under-pressure in the drain system - Correct ventilation of the drain system is important - The odour barrier opens and closes with the help of a spring - A rubber seal ensures that the odour barrier is closed when not in use
