bought an AC adapter. Asked the (clueless) vendor whether 5V meant 5.00V+-0 or something else. Vendor said, sure it's exactly 5 volts.
Now I got it and my voltmeter says 5.15V. Rumor has it that anything <5.3V is safe but the adapter wasn't too expensive and I'm afraid that loaded it could have voltage peaks. Any hints.
It's rated 2.5A @ 5V ("stabilized"). The product is called "Electronic 2.5".