I'm replacing a couple of ceiling lights, currently with a ceiling
rose with 4 cables going to it (supply in, supply out, switch, lamp).

The new light fitting replaces the ceiling rose but just has a 3 way
terminal block in it's base, and no room for all thos cables.

I've seen mention in here in the past of a junction box where all the
cables can be joined and it just pushed back up into the ceiling void
via a relatively small holes that will be covered by the new light
fitting. The box is suitable for limited access use, and has strain
relief grippers built in. Getting under the floorboards above will be
a real pain.

I can't remember what it's called, Anyone help?