Useful if you ride in urban areas, as air pumps fitting for schrader valves are plenty because like every car uses them, sclaverand or even dunlop - not so much. Just screws on, fill tyre, go about your way

Are they high quality? Nah, wouldn't really use this in a workshop setting. But to put on your keychain or something in the event you might need it? Pretty good! And they're cheap enough if you find a miserable soul with a slow leak who didn't plan ahead you can just give it to them