I have not yet had the opportunity to use this light and I have a number of issues with it. The English language instructions are horribly written, often to the point of being incomprehensible. It does not make sense to fasten the light to the seat post as it can be quickly removed and tossed. When parking the bike I fully intend to remove the seat and battery. Again how will the alarm help if it is in my hands. I most likely would not have purchased the light if I had known of these issues. The company needs to rethink how the light is to be permanently fixed to the bike. All this being said, I believe the light will enhance my and my bike’s security while out in the community.