PLB question, possibly stupid

My dad just bought me a PLB because he stresses when I go bushwalking alone. I've just registered it like the box said to do. I have no idea really about anything to do with them. Just wondering, so the battery lasts for 7 years apparently, once it's been activated (fingers crossed it never needs to be), will it work again after? Or are they single use things? I know it's probably a silly question
Thank you! I'm completely clueless. I think I need to read up more on how to set it off/test it etc!!

Thank you! I'm completely clueless. I think I need to read up more on how to set it off/test it etc!!