Here is a nice lens cap that works well with the SmallHD sidefinder to protect the panel from sun burn.
Any 46mm Lens cap should work fine.
You can also open the sidefinder when you are not using it which will help you avoid sun burn on your panel.
Here is a link to the pin out of our hirose connector- you will need this as a reference when looking at the wiring diagram
https://www.smallhd.com/support/faq/hirose-pin-out543/ring diagram above.
Unfortunately the 5d MKII Port Protector only works with the 5D MKII not the 5D MKIII.