This is a 4 way, 15 Amp mains electrical junction box, suitable for lighting circuits.
Electrical connections are made using terminal strip (actually Wickes UK product, 710111, but other 15 Amp strip will probably fit)

It is more compact than the conventional circular hard plastic junction boxes, and in my view easier to wire. It will accommodate a 4 terminal block which might be needed in a 2-way switched circuit.

Lid is retained by 2 M4 x 12 mm countersunk head screws, which attach to M4 nuts embedded in the box part.

Easy PET-G print. Need to set a print pause at the upper face of the M4 nut pockets. Drop the nuts in then complete the print.