Lauren, I like these although more expensive....the hat clip has come in handy many times and much thinner the the one you posted takes one AAA...I also have a two AA version that is about as long as a pen but a lot thicker
http://www.streamlight.com/en-...product.html?pid=144 One AAA
http://www.streamlight.com/en-...product.html?pid=133 Two AA