I fitted one, you can buy them online,I attached it to my van, I took it to a body shop and he drilled a hole and attached the socket, I then took it inside to a cut- out fuse box bought one from a Wholesale Elec shop, (it was for a shower unit), mounted a three way socket and wired it up, worked a treat.
I know what you mean, you want a hookup lead that combines a 3pin domestic socket at the caravan end, yes? I guess you have seen these on the continent, but these will of course use 2pin continental domestic socket? I've not seen a UK version of these except lashups on ebay that use a short piece of lead wired into caravan socket(do not buy one)but as pointed out, not a good ideal as it cannot use the caravan rcd protection so a better idea as pointed out is to get an external socket installed on caravan,
I wanted an awning socket but didn't want to cut a hole in my brand new caravan.
I built what is essentially a tent type EHU, it has a 16A inlet that my lead plugs into and a 16A outlet which plugs into the caravan. It also has 13A sockets with waterproof hinged lids, all protected by RCD/MCB
A day of all things motorhome and campervan. The show is held both in the main indoor arena and across the grounds. Catering, hot drinks and food options are available. Easy access to the site and free parking included. Win one of five pairs of day tickets