This Z brace is for the Sidewinder X1 and uses 15mm(UK) or 16mm(1/2"US) copper gas/water pipe 600mm long on each side. I used 10mm M5 screw for the top brackets and 10mm M4 screws and nuts on the clamps.. 12mm M4 on the rear brackets. I used PLA without any problem but PETG would probably be better