The Ride Pro Aquazero arm warmers are made in Italy but designed with the UK climate in mind. Super Roubaix panels are sewn into an anatomical shape with a bend in the elbow so they don't bunch up when you're on the bike. They have silicone silicone grippers top and bottom to keep them in place.
The Sportful No-Rain arm warmers perform a lot like regular arm warmers except that, as the name implies, they are also water repellent.
There's not much to say about arm-warmers, you put them on and they keep your arms warm, or you take them off when they've warmed up. They're handy for changeable temperature conditions when they can be slipped on and off as heat and chill dictate. They can come in different colours to match your socks.
End of test.