http://www.shockmount.com/page2.html
I've got several of these shocks. Don't use it to hold your heavy, smooth tube mic vertically, as it won't (bands are elastic, not rubber), but great for end-fire type mics, especially something with 'ridges' all down the length of the thing like an RE20.
I use a pair of these for my RCA BK-5B ribbons, both of which are missing their yolk mounts. These work perfectly.
Great price too.
Joel