My wand didn't come with any attachments, so I bought this--and it's really good.
It actually enhances the stimulation from the vibrations, so it actually rubs you. This means this is perfect for those who love overstimulation, as you can quite easily position your wand in such a way to keep it going.
It's nice and tight around your shaft, so it squeezes you back and forth--it's too tempting to thrust.
I'd recommend using it with lube as, even with a foreskin, you'll get a friction burn and it just won't feel great - you don't need too much, but the more the merrier.
This attaches tightly to the wand, and the silicone provides a seal that keeps it from slipping off, and allows you to attach it at an angle without it moving.