Thanks guys! It’s 4.6kgs, but I’ve had one hanging on a decent screw and real plug (into a solid wall - wouldn’t recommend for stud walls!) for ages. It’s only a shearing force - there’s no moment to speak of.
It’s about 30cm - here’s a pic with pen for scale. Also shows off the colour better in daylight.
The metric thing is frustrating! Very few cars have 6 or 12 mounting points. LMP2 cars tend to, from my extensive research on the matter!