Review on Stay Safe And Visible Anytime With GPMTER Ultra Bright USB Rechargeable Bike Tail Light - Perfect For Road And Mountain Bikes by Isaiah Boys

Mounting System is a bit cumbersome. I prefer vertical on my bike. The release tab on the mount lines up with the light which means that you might have some difficulty when it comes to install and removal of the light. I have a similar light that is being replaced by this one which has the tab in the horizontal position. You can pivot the light to your liking which can remedy this however you may need to loosen the screw a bit (see attached pictures).Lumen output is 100. I got these because I like to have one on each side for visibility.The charging port is on the rear. Time will tell on the longevity before it rips off. Also a bit cumbersome because it needs to be inserted into the charging port for it to sit flush.I haven't had a chance to experience the functionality of the battery life. For the price this is a good buy if you're looking to be seen.I ride at all hours of the day between 2-4 hours. You may want to consider another set to have as a backup.