Not a bad tank bag, even if it's on the smaller side. I can fit a spare visor, spare pair of gloves, sunglasses, turtle neck neck warmer, and the liner to my jacket in it, no problem.
I cut the rain liner out of it, since it took up a lot of room, and I'll never use it. The cell phone pocket is useful, and it allows to see a part of your screen. I use the CD player pocket to hold my wallet, and keys, since I haven't owned a "Discman" in about 15 years!