It’s hard to nail down OS. The www.oregonscientific.com website redirects (for me) to https://store.oregonscientific.com/us/ and the only professional station that site shows is the WMR86NS. There’s also https://www.oregonscientificstore.com which I think is a dealer, they show the WMR300 but it’s “out of stock”. Google finds a WMR500 “out of stock” page on that site, but I can’t find it linked on the site menu :dontknow:
Even if the WMR300 is discontinued as we suspect it’s pretty shoddy to refuse to supply parts for what was a relatively expensive station :roll: