This is one of the brightest lights I have ever seen in such a small housing. It fit on my handlebars perfectly although at first I was worried about the way it attaches. The attachment is just a band that hooks onto hooks on either side underneath the housing. It does come with two different size bands for attaching the light. I was disappointed that it didn’t come with any instructions at all but after playing with it for only a couple mins I had it all figured out. There are three different brightness levels and a strobe. To switch the levels of brightness you just push the button on the back and to get the strobe effect you just hold the button for a few seconds. The included battery pack has a Velcro strap which is really handy. It also came with a headband and a wall charger. There was no discernible heat from the unit even after being on for a couple hours. I had it running for a couple hours and the battery was still going. I have not yet found out just how long it will last on a full charge.