Previously had two other slides that have safely and evenly poured out the water - but black, so that by the time all was a black border. This here is the only white slider, I could find (someone has an alternative?). This looks great, is easy, but can be on both edges traces of water left. (The foam may not be improved by hand ...)
Conclusion: ok, but not as good as many others in the feature, but knows - and does not leave black residues with time.