Why are the X1/X2s for “temporary use only”?

The units are tough and robust, but only for temporary use. If allowed to sit for too long in the same position, the seals may be compromised. They are designed for use with power tools, connecting a market stall, or at a campsite, and are meant to be disconnected and stored away after use. To seal connections longer term or permanently, there are special joiners available from trade dealers. These generally involve potting the connection and rely on screw-assembled housings.