a recreation of a pool skimmer flap door that fits Olympic brand skimmers.

modeled from an original part, however this is lacking the water flow guide fin, but in my experience that did not seem to be an issue, YRMV.

the model is also available on GitHub for both the STL and openSCAD model.
https://github.com/bicknrown/models/tree/dev/poolSkimmerDoorFlap

the part measures:
154mm from the edges of the pins.
141mm for the main body lengthwise.
111.5 mm wide for the main body.
19 mm tall.