I’ve just got an E05R keychain light and it’s very cool. It came with two spare O-rings but I’m somewhat puzzled as to how they’re meant to be replaced. Do you just have to stretch them over one end of the light to get the new ring on? I don’t think there are two parts of it that come apart…
If you don’t pinch it, the original should last a long time.
Yes, just stretch the old one off, then stretch the new one on. It will stretch enough to get over the head.