Try this eBay eBay search http://www.ebay.com/sch/i.html?_from...All-Categories

I've attached these to both a TerraTrike Cruiser & a Gold Rush Replica. I find the Q5 5W/7W LED flashlights provide more than enough light to illuminate totally dark bike paths - and they are easy to attach/mount. Just be sure which battery(ies) you'll need for the light you order - some are 18650, some AAA, some AA. Rechargeable batteries, a charger and you're good to go.

I use a 3W as a hemet-mounted (backup) light.