MetroFlash Danger Zone Tail Light

does it have a clip to mount to a ToPeak rear bag

I forgot. How do you open the light to get to the battery?

Does this light have "mode memory", so you don't have to cycle through all the options every time?

Is there someway to mount this light to a rear rack? Or perhaps the clip works with an adapter like this one: http://www.amazon.com/Planet-Bike-Tail-Light-Bracket/dp/B000IQEAK2 Thanks!