Review on Stay Safe While Cycling With G Keni Smart Bike Tail Light - Auto On/Off, Waterproof, USB Rechargeable, And Ultra Bright LED Warning Back Bicycle Flashlight! by Loren Slama

This is a nice bright light, easily visible from a distance in daylight over a reasonable range of angles from the rear. The mount is very good. It is solid and secure and about as high on the bike as anything can be. It is well constructed, with an aluminum body and aluminum screw-in receptacle on the mount. The button is firm with distinct tactile feedback that you have pressed it. The battery strength indicator lights are very small but visible. There are four modes, only two of which I use. The first two have auto-on and off features that I don't trust and flashing patterns I don't like. The third one has a an eye catching strobe that I normally use to be visible to cars and the fourth one is steady on for when someone is riding behind you and the strobe would be distracting. The brake light feature works pretty well, which is also good for when someone is riding behind you. I like it so much I bought a second one for my daughter's bike.