no the single aa is smaller about as long as a bic lighter and about as big around as a wine bottle cork. They also have just bright/off ones too if that suits you.

The 3 aaa one is about as long as a minimag but about as round as your standard small LED types. These lights use an SMD wafer thats the next step up from leds. if you focus the beam tight you get a spot pattern that looks like a piece of toast. This is the wafers shape. Adjust the beam and it grows but loses intensity.

They are great for the price and you'll never want LED again. I purchase about 10 of each to pack or give away

The big one could be affixed to a hat I reckon, but the little one would be better.