I use the Terralux Lightstar 300 flashlight from Amazon. Held in place with a two fish lock block. I like the flashlight because its cheap, compact, easy to remove. Less desirable to a thief (I think) than your bike specific light. Speaking of which. I'd put the $28 lightstar up against any $150+ bike specific light. Sure, some bike specific lights may be brighter. But not by much. At least not to justify the price difference. And a similarly priced bike light would be junk compared to the Terralux. And no way a $20 bike light will come close to the 300 lumens of the lightstar. The lightstar also uses AA batteries, which are everywhere. I use quality rechargeables. I've used the same batteries for over six years. Which means the batteries and charger(LaCrosse) have already paid for themselves. Talk about durable. I've used mine in all kinds of weather. From sub-freezing temperatures to pouring rain. I get about 2.5 hours of runtime on a set of Eneloops. Cars see me, and it has a wide flood with a nice spot in the middle. I use two tail lights that I get at the LBS for about $12 each. The more the better.