Review on 🚴 Padonow Smart Bike Tail Light: Auto On/Off Flashing Red LED Lights, Easy Mount Cycling Safety Brake Taillight - USB Rechargeable, Ultra Bright, Light Sensing Bicycle Rear Light by Juan Simpson

Good form factor, very dim Good: Screw on and pretty easy. Not too hard. Bad: very dark. This light is almost invisible under my seat. When I turn on the light, it doesn't illuminate the rear tire at all. I can't usually even tell if it's on unless I lean in and look at it up close. Since it's advertised as "Ultra Bright", I feel like I've been ripped off. Ultra dim is more like that. I can't tell if the motion sensor is working or not because I can't see the light. Good: nice form factor. Hidden under the seat, secured with Allen screws. It's a clean lock and if bright enough such a mount would prevent drivers from being blinded by direct light. Unscrew by hand to remove and charge. Fair enough, the battery seems to be doing pretty well, but despite being so weak, it should be better. Conclusion: should be at least four times brighter. It's so dark it's barely visible. Not recommended for daytime use as no one will see it and you will easily forget it is on when you park your bike. Only use as an additional light source at night. Otherwise, it's a well-designed, beautiful, mostly ineffective, low-light accessory. Car brake lights typically have 400 lumens but can have over 500 lumens each, and cars have two. On the contrary, this bike light is optimistic, maybe 30 lumens. Tucked under my seat, it's almost invisible in car lights. This tiny 30 lumen light cannot compete with cars whose brake lights emit 800-1000 lumens. Maybe it's useful on paths with little traffic or as an extra light.