If you are in the market to increase weight on your Moomba, check out ebay seller NTSHULL. I picked up a 700# sac with pump and colored cover for $135 shipped. I just tried it out this past weekend and it was awesome. It was a totally different wake then before. I coupled this sac with the stock tank in the ski locker of my04 Mobius ls and was very happy. Needless to say, I will have to get used to the huge wake my boat puts out. If you need the sellers email address, just let me know.