Are you on about the connection between the fixed wiring & the wiring/leads to the LED lighting?
If so, normally a suitable JB, I've used Click Flow 102C. Or as is common in new builds, fixed wiring terminated in a flex outlet plate (& back box).
If so, normally a suitable JB, I've used Click Flow 102C. Or as is common in new builds, fixed wiring terminated in a flex outlet plate (& back box).