Does anyone know please what kind of fitting this is? I have hot cold wallmounted faucets for a bathroom basin. The original taps (pictured were not gripping and slipping around the pipe)I was told by a plumber that he couldn't find any similar taps with a fitting like this (some sort of import?). I am looking to replace with a separate tap and h/c Grohe faucets, some of these require their own concealed units though. Ideally I'd just replace the faucets with something like for like but i'm not opposed to the extra work of having the wall tile remove. Any suggestions welcome thanks.