BSSOK Smart Bike Tail Light, Ultra Bright Bicycle Brake Light, Super Sensitive Auto On/Off Bicycle Rear Lights, USB Rechargeable IPX6 Waterproof Daytime/Night Riding Red Safety Warning Back Tailligt

It is easy to mount, with its elastic strap, so if I want to move it, say onto a trailer, no problem.I like that I can leave it on auto, so when I move the bike it turns on, and when I brake it lights up.It also daytime detection, so only the braking sensor works during the day.It is easy to twist it off, and recharge it, with a usb mini plugThe Bike Buff

This little device is bright and works as advertised. I added to my sissy bar as an extra light to get drivers’ attention. I would have bought just for the light but it actually senses when you come to a stop and gets brighter. It almost acts like a second brake light. It may not work perfectly, (Can’t tell when riding) but I am happy was the product and the price. Well worth it for a little added safety.

The light is bright and stylish. Fits nicely underneath the bike seat. Well made. Only problem is you can't turn the brake function off. If you hot a little bump, it will trigger the brake function and it does this every little bump you hit. Battery would not last long at all. Other than that one issue, it's a great light.

My daughter uses one of these on the back of her ebike to ride to and from school. She leaves it in automatic mode and it works great. The light is sensitive to any kind of movement, so as soon as she gets on the bike it turns on and stays on until the bike is stopped for at least 45 seconds.

Crap! Plus the customer support is a FAQ nobody to contact about it not charging after the first time.Brightness was great unless it won't hold a charge...

Nice it has mounts for seat rails and band. The manual/auto switch works but so intuitive. Put it in auto and its fine. The screw in/out mount to charge or auto switch access takes a little getting used to. It is bright enough and the auto on/off, brake light, and flash mode works great.

The media could not be loaded. This is a great idea for a product I've wished for a long time someone would introduce: A bicycle tail light that also operates as a brake light. It would be fantastic to let vehicles and other bike riders behind you know when you're slowing down, especially when you're braking hard. I was excited to get one. For those who don't like reading lengthy reviews, here's the Bottom Line: Based on my experience, if anyone's thinking of buying it for the brake light feature I can't recommend this product. If all you're looking for is a taillight and you don't care about the brake light functionality, it will serve that purpose pretty well. For more, please see the Pros and Cons below:PROS: QUICK BATTERY RECHARGING, LONG LASTING CHARGE: The battery takes a full charge in a relatively short time, and it holds a charge an impressively long time. I've operated the light at least 6 hours since first fully charging it and it's as bright as ever. I have no doubt about their claims as to battery life using various "modes." When I recharged the battery after all that use, it had a full charge within about 45 minutes. Excellent.GOOD CHOICE OF LIGHTING MODES: The variety of modes for the light are extremely useful: Flashing, pulsing and steady illumination all allow others to see you as they approach from a very substantial distance. The light has great brightness, regardless of mode, and it's a good choice as a tail light.SIMPLE OPERATION: Operation of the light in either Automatic or Manual and switching among modes are simple (although changing from Automatic to Manual isn't as convenient as it could be). See comment below, under CONS, about using the Automatic mode.BRAKE LIGHT BRIGHTNESS: The "brake" light illumination is substantially brighter than the tail light's brightness and - when it works - probably gets the attention of those behind you. See the accompanying video.WATERPROOF: The IPX6 waterproof rating is reassuring. It's nice to know that rain or splashes from puddles won't affect the light's operation. (I didn't test it with a garden hose. I'm trusting the rating.)CONS:BRAKE LIGHT OPERATION: The brake light is unreliable and, in my tests, only worked in one of the light modes (one of the flashing ones) and even then it only came on maybe 1 out of 5 times I slowed down. I tested all 6 modes. I tested Automatic and Manual. When the brake light did actually come on, it was usually when the bike was already almost completely stopped. It never came on at the beginning of deceleration, no matter whether I squeezed my brakes hard to bring the bike to a sudden stop or brought it to a gradual stop. Several times the brake light came on as I resumed peddling!AUTOMATIC MODE: I tested it thoroughly using Automatic Mode. Really inconsistent results. In Automatic Mode it's supposed to come on when light gets dim and shut off if you stop the bike and don't move again within 45 seconds. It's supposed to turn back on when it detects movement of the bike. It did turn on automatically when I took the bike out after sunset. Great so far. The problem was that if I stopped the bike and got off, the light would sometimes remain on for only as little as 5 or 10 seconds. Other times it remained lit the full 45 seconds it's meant to stay on. But twice it shut off, only to turn itself back on and stay on another 45 seconds or so. So, if I parked the bike in the garage for the night I wouldn't know if the light was going to keep turning itself on during the night. I suggest that if you're going to ride your bike in the evening or night time, forget the Automatic mode and just put the light in Manual mode and leave it there. The battery holds a charge well enough that you won't run it down if you leave it on for a few minutes when you park your bike temporarily.ATTACHING THE LIGHT TO YOUR BIKE: The components for mounting the light under the saddle are not a "universal fit" type mount. The clip wasn't long enough to seat properly on the bars under my bike's saddle. I used the rubber strap instead to mount it on the seat post. (It would have been nice if they had included 2 straps instead of just one.)SWITCHING BETWEEN MANUAL AND AUTOMATIC MODE. Minor inconvenience: To switch between Manual and Automatic mode, you have to unscrew the light from the mounting bracket. I recommend just leaving it in Manual and turn it on any time you ride. A tail light is useful even when there's daylight, because it helps get you noticed by vehicles approaching from behind you.A NOTE ABOUT THE VIDEO: I mounted the light on my handlebar temporarily to make it easier to shoot the video illustrating the brightness of the brake light. I tried having my neighbor shoot video when I mounted the light on the seat post, but the brake light only came on occasionally and we had time getting a video that showed it clearly. When the bike was stationary I could get the brake light to come on by just tilting the bike or turning the front wheel.

This is the second one I've purchased and have been happy with both. The first one left with a bike I sold. Very convenient light when set to the auto on mode. It works 100% as it should and looks to be well constructed and solid.