Andrew Gabriel wrote:
In article ,
"Grumps" writes:
Ta. That's the answer I like.
Available units (Screwfix ranging from £20 to £50) all have 30mA
and at least one is spec'd at 30ms (regs say 40ms).

Watch out to ensure existing back box is deep enough.

Thanks for the warning.
The cheaper Volex one from Screwfix needs 25mm. Not sure about the MK one.
There's one on TLC that also needs 25mm. I guess they'll all be the same; a
bit stoopid if a manufacturer made a deeper one.