I wanted a better, more water-resistant and dust-proof connection between my Power Bank external battery pack and my Akasa Action Sports Camera on rides. The battery pack sits in the rear webbed pouch of my saddle bag, a few inches away from the camera. The cover and plug will help in making this a water and dust-resistant setup.
Power Bank 25800mAh External Battery Pack (Amazon): https://www.amazon.com/gp/product/B07TSHW85D
Both the cover and the plug should be printed standing on their open bottoms on the bed. If you're using Cura you will want to use Tree Support on both, with or without a brim as needed.
The cover will be a snug fit, with the middle tab useful in removing the unit when it's time to charge the pack. A USB cable will be a worry-free snug connection. The plug isn't as snug, so you may want to increase the size by 101% in your slicer if you care. Silicone sealant over both connections will make then water-tight, semi-permanant, attached to the removable cover.
I used PETG for durability and heat resistance to outdoor riding temps in my locale. PLA/PLA+ might work, but if your area gets really hpt in the warmest parts of the year, it might be better to go with a higher temp filament. ASA, ABS, and Nylon would also work well, but you may need to adjust the sizing in your slicer to compensate for shrinkage.