.....there is also a very unique seal running around the outside edges of the slider that will seal up the unite even when vibration is an issue.....[which I took a pix of-kinda] I'd say in the enviroment that these sleepers will operate in that they should stay completely dry as opposed to the seals that are put on RV slides that I have seen.....[these are sawtooth].Another issue on slides, is that around sand dunes you should not use any wet lubericants because the slides will seize up when the sand clings to the slide material.....spray the slides with a silicone [dry] lubericant before you leave for the dunes and wipe them with a clean cloth before closing them.....makes good science no matter where you are camping....-this was from a guy at the Louisville show as per all slides in general......geof kaye