Get both ! you can find them on Ebay for 35 bux a pair. I love my fleas lol Had the front one for about a year and recently got the back one. The front one has a velcro strap that fits anything, the back I believe comes with a strap as well but the cool thing is that it has a clip so it can be attached to anything. When commuting I have it attached to my bag, when on the road bike I have it on the side of my jersey.