ROCKBROSBike Tail Light Smart,Brake Sensing Bicycle Rear Lights for Night Ride,Ultra Bright LED Back Lights,Type C USB Rechargeable,IPX6 Waterproof,Cycling Safety Taillight Accessories

UPDATE: Rockbros refunded my purchase price, and I will re-buy when they make a unit that has auto on/off and motion sensing in the daylight. Outside of that, it is a very nice unit. Small and bright, with a good mounting system. The brake light algorithm seems to work well.UPDATE: The Q5 is a Tail light.The one I have, does not have auto on/off, motion sensing in the daylight - despite what RockBros.says. In fact, if you very carefully read the PR info, it says this.The tail light has manual mode, strobe flash and contiguous in the daylight, not auto on/off motion sensing.The RockBros Q5 tail light Has several problems. There is no way to shut off the ambient light sensor for the blink and breath functions. This makes it useless in the daylight and only useful at night. So the kid riding to and from school does not have a tail light, which is why I bought a vibration sensing/auto shutoff light in the first place.The manual says that mode 3 and 4 (strobe blink and continuous) are useful in the daylight, but they do not have vibration sensing or auto shutoff. So to get into that mode you have to push the button through all the other modes, and same to shut it off - not very "smart".So, I took the unit apart (thus voiding the warranty) to see if I could cover up the ambient light sensor. That didn't work because they use the off cycle of all the LEDs to sense ambient light. So, I had to block all the LEDs to keep it blinking in the daylight.I asked this question before I bought it, and got an inexact answer back from someone who is not a native English speaker.

gotta say, best tail light I have tried.was skeptical about the mount system but after a couple months, maybe 12 rides on fire roads and single tracks, and a few mild crashes,( but a very bumpy ride each time) this light has continued to work flawlessly.the mounting system has held up.the battery has lasted well.it is bright enough.easy to unscrew and recharge.good price point.giving it a 5!tho, not sure about the brake light since i dont follow myself ;-)recommendation....buy it

My only gripe is setting 1 and 2 sense the sunlight and turns it off, which might be a feature your want... But I want it running during the day, but if your click it to setting 3 it stays on, so problem solved but it wasn't obvious when I got it and I was scratching my head trying to figure out why it was off.. mount interface is solid, great design, and I love how it detects you're slowing down and acts like a brake light, ppl mine be less mad when I roll that stop sign (hehe) as they can see that I was at least 'slowing'..

Not a really expensive light, but not cheap either. Wasn't sure where i'd be on the value equation with this one. But I actually really like it. Battery life is more than I expected. I love the subtle battery level indicator (how many tiny blue lights are on in the center ring when it's on). Screwing off of the mount seems so much better than some of the clip-on styles I've used before (on bike-store brands even!). The way to cycle through the modes works well for me - I can reach around while riding and cycle through to what I want. I can't see it while riding so I can't comment much on the braking function (and I ride mostly solo so no one to ask).Rockbros seems to have some really good stuff and some okay stuff ... seem to resell a lot of items that others have too... so maybe you could get this light under another 'brand' too. Whatever, its a good solid "mid level" light, better than a lot of budget lights but not costing you a premium. I think it's a very good value.

Nicely made with a machined aluminum housing, mount and seat clamp. Really nice to not see plastic! Love the auto-off and 'stop light' feature. Battery life has been good and the blue indicator dots are helpful.You can't compare this with a strobe type light so if that's what you want I think the brightness will be disappointing. I wish there was an option to run the light full time at the stop light brightness even at the expense of battery life.