Optimus is hollow and has a hole in the top of his head allowing for a light bulb to be plugged in. The plastic is very light and translucent. The ornament is about the size of a current Scout class figure. Unless you are using LED lights they don't light up the entire ornament sadly. Overall it's a neat little novelty item, but one that I no longer have a need for. I'll be putting up all 4 for cheap on Crave soon so if you must have these on your tree next year here is your chance!