The Bilsom 303L are not quite what I had imagined. The sound is really good, they are very light and go fast after squeezing apart again. You really have to but after the press remain pure in his ear with a finger on it, otherwise it will slip back out. In my right ear I get back only a poor insulation, although they do not get slipped at the end, but obviously not quite stay indoors. So stable and reliable, the 3M 1100 SP.
