Having already my old Sigma BC 506 (who was already getting on in years) absoff in the rain, I wanted to get me a new one which must be wet sometimes ... Since I do not re-wrap the whole cable stuff around the fork and no wanted to spend a fortune for a wireless, I opted for the Sigma BC 1009 the first took care of the old "base" from BC 506 & 2 should be loud Sigma website "WATERTIGHT". I can not complain about the functions of the speedometer, which has everything that interested me and the basic settings are also very simple to make - hence strong buy recommendation & 5 Star! But after the first ride in the drizzle (maximum ne quarter of an hour !!!) was also here back layer in the shaft and the screen showed nothing more ... now after a day in the sun at the window you can already see the condensation under the Display & it should be like the old speedometer, he works tomorrow hopefully again when all the water is out ... Still, it's really a pathetic "performance" for NEN Waterproofing brand Speedo ... I would be interested in other times experience in terms of water resistance - the possibility exists of course, that I caught just NEN Monday speedometer. And: the tachometer is in perfect condition: he has never fallen down or something else, so he could have cracks, could come in through the water ...