They come in 8, 10, and 12. I purchased a 12 BP about $400 for the box and sub, and im extremely impressed with its responce. Im in the process of geting a 15 XXX for my car, cause im running a 1200D to that BP12, at 4 ohm, my amp puts out 700watts at 4 ohm, which is a little to much for it. There website shows it. I dont know about the other subs. I havent heard any of them other than the BP series.