Question about Dri-Box 285

I left it for a month directly in the rain with an indoor power strip without any problems. The important thing is that the various slots are closed properly.

Depends on where it is used... If in a secure, dry place and with a roof over it, indoor material is probably fine (but no water from the pool should splash on it, etc.). But if it's placed in a ridge / on the lawn or buried and without protection from the rain, then only outdoor material will do - otherwise you might get a whistle in your socks when you step onto the wet lawn. The housing shields you from splashing water, but standing water or moisture will of course get in.

Normal plug is sufficient.
For 5 years without any problems on a covered seat.