Occasionally, customers will report that the FV Series transmitter they just bought has a lengthwise crack in it, which would let water inside and probably ruin the electronics. We have yet to see one of these transmitters that actually had a crack in it. Instead, what looks like a crack is an artifact of the molding process when they are cast in resin. It is a mark left by mold halves that are not perfectly aligned, but this is only a cosmetic problem and in no way represents a defect in the transmitter.
The photos below show what these “cracks” look like. If you think your transmitter has a crack, look at it very carefully. You’ll likely see that it is just unevenness in the plastic and not a crack that goes deep (click on image to enlarge).
However, rest assured that if we ever saw a transmitter that actually had a crack, it would be replaced under warranty.