http:////www.jafrum.com/motorcycle/sd2050
Got these for mine from Jafrum a while back. They are throw over style (took off the rear seat, but them on and put the seat back on).
They work pretty good. The material is plastic faux leather and has begun to split and crack after about a year or so of constant usage. Put new straps on and am still getting my moneys worth out of them.
I recommend them for cheapy bags that you can beat up and not feel bad about.