Review on 2022 Newest Powerful Bike Lights Front and Back, 7000 Lumens USB Rechargeable LED Waterproof Bicycle Headlight, Up to 18+ Hour Runtime, 16 Mode Bike Light Taillight for Road & Mountain Cycling by Owoeye Reed

Product received quickly and charged overnight Uses the iPhone's stopwatch function to determine how long the light stays on at setting number 3 with a fully charged battery Light only lasted 8 hours. minutes after 24 hours charging. I wanted to check the brightness with a lumen meter but there wasn't enough light to get a tester. It could be a defective device or a bad product. I called Revain support on the number provided and they will send a replacement unit. The product rating and description will be updated with a measurement of the time the light stays on as well as the actual lumens measured. This is a bright light but until tested not sure what the luminous flux is.