water service flap for the motorhome.
the whole should be printed with a weatherproof and uv resistant filament.
inside it has Garden Hose Quick Connectfor to connect a water hose. you need a matching o ring sealing ring.
also you need a switch with 28mm x 13mm installation size. in addition two flat plug sockets. with these you could operate a pump or something else.
i got the lock from aliexpress. the shaft of the lock should have a mounting depth of 20mm.
glue the connection tube on the backside with silicone glue.
installation size of the housing 100mm by 100mm.
to connect the cover to the housing you need a 4mm thick screw or rod. to fix the cover to the motorhome you need countersunk screws which are not too wide but long enough. and i recommend to mount everything with silicone glue.

weatherproof and uv resistant filament. weatherproof and uv resistant filament.