This is a genuine Garmin branded mains plug-in 5v transformer. It comes with a dedicated 3-pin adaptor for the US 2-pin original, which pushes right over the 2 pins in a very tight and solid way, so no wobble, please see the photo.
The condition is very good, with few wear and tear marks.
Ebay has non-Garmin ones at around £7, so I am asking £6 for each of these or £15 for all three .
Buyer collects, or I can post this at cost, currently £2.80.