Top and sides. There is a technique to the install (having watched Phil do it on all 3 of my bikes). The protector is stuck down with very strong double sided tape, as used on auto trims. Before removing any backing tape, the tank is cleaned and the protector is positioned and key points are 'marked' on the tank using removable tape (ordinary masking tape works well). Then all the backing strips are removed, and the protector carefully positioned using the masking tape as reference points. Then it's all smoothed into place.
Trying to describe this makes me think they should post a YouTube video. I'll suggest that to them.
Just to confirm, I have no affiliation with GCC, except as a happy customer (who pays full retail for all products). Phil, the owner, is a dedicated biker and I just like his attitude, and their products are great, so I will happily recommend them.