I bought for reasons of design this pop valve. The rubber sealing lip is however so weak in the chest, that the valve slightly dripping closed in front of him. That is, sooner or later (rather long) is the sink empty. The amount is small, but kind of annoying (drip, drip ...) Otherwise, there are still problems with the overall length of the so-called space-saving operations under the basin, because in drawer vanity unit. I've shortened the valve to 20mm. But more is not because the pop mechanics also still has to stay somewhere. Then super fit from the square. Would be good if the dimensions were given. For normal operations with trap no problem. Due to these minor inconveniences only 3 points.
