1st question: what is purpose of using a high current GFI (Leviton #8895) with attached doughnut?
2nd question: Anyone have a replacement for this, as Leviton has discontinued it?
3rd question: Would a regular 20a GFCI work in a situation as follows?:
Control unit for a pond areator, installed 2013. 120vac power goes through GFI then to timer, hoa, motor contactor. Load from GFI goes through doughnut, as does the 240v power leads from contactor before going to areator motor, which is a submersible pump floating on a pond.

Any help would be appreciated.

Rick Miell