I've had this light for about a year and a half and recommend it. It is very bright, has one focussed lens for throw and one diffused lens to spread the beam better (should be mounted horizontally to take advantage of this feature). It's a simple and sturdy design with good rubber sealing and a prominent central button with good feedback which lets you switch the light on easily while wearing thick gloves. I am also able to reach around and switch it on or off whilst riding eg. through a tunnel or through a dark tree section during the day. Battery life is decent enough. The seatpost mount is solid and hasn't broken on me yet, the light also has a sturdy clip that can be fitted to bag/clothing etc. There are a couple of small niggles. Firstly the switch doesn't always operate every time you press it to switch modes or turn it on and off. It's never been too bad in this respect though. When mounting the light on the seatpost bracket you need to slide the clip on the unit into the bracket and it secures with a small click sound when it locks into place. You need to be quite careful that you have pushed it onto the mount properly for it to be secure, as it's quite easy to get it wrong. Once it is on properly it is very solid. Overall it's definitely the best rear light I've used, and is pretty cheap too these days.