It arrived 80 percent charged and I talked on the phone for more than two hours and the didnt die. Small but heavy enough for a variation of exercises. The first pair the sole separated from the shoe. For all those complaining about they didnt come with bolts to attach to the bike, you are supposed to use the bolts that hold the rear wheel to the bike. No more reaching for a container only to find it almost empty. It whistles, doesnt notice the whistling when i had cargo carrier on it. The only snag is the sizing: the first two pairs were fine, the next from a different supplier were much too small although I ordered the same size apparently. My cat lost my charging case so I needed a replacement fast. Rough and nearly single-track? Check! Look like they have a durable sole but this does me no good when I can’t get the right size