A BNC cable connector rain cover, to offer some degree of protection against the elements.
This was designed to protect a loop antenna coax cable connection. The cable hangs vertically below the amplifier box BNC connector and the rain cover acts like an umbrella.
The sleeve washer fits beneath the connector nut and washer and should be sealed against the box using glue or a smear of silicon grease, to prevent water seeping between the parts. The sleeve is a push fit inside the sleeve washer, no glue required.
A 14mm BNC fixing nut driver is included, as the nut is recessed inside the sleeve washer. It has a hex hole for a pen or pencil to act as a lever, though I found I could easily tighten the nut using the flat end, without a lever.
The sleeve diameter is large enough to take a BNC to SO239 adapter, for use with a PL259 cable. Such an assembly requires a longer sleeve, which can be adjusted in e.g. Cura slicer. The default Z axis dimension is 60mm long, which I adjusted to 90mm for such an assembly.

Updates:
1) BNCthickerRainSleeveWasher.stl is made marginally thicker to produce an extra layer in the base and walls, due to the part splitting along the Z seam. The BNC thread hole is marginally bigger.
2) BNCshallowNutSocket.stl added, which has a shallow (3mm) hex socket and the remaining hole is round. This prevents the nut falling inside the socket and makes it much easier to start the nut on the BNC thread.
3) All parts are printed with 'Z Seam Alignment' set to Random (Cura) to remove weak seams.