Help!

Hi,
   I bought a ring stretcher from eBay and it came without any
instructions. I am a rank novice as it is, and I can't figure this
out. (We didn't do this in the jewelry-making class I took in '91)
  If anyone would be so kind and generous with his/her time as to take
a look at the page and tell me how to use this (you can't dumb it down
too much) I would be eternally grateful.

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=360038043257&ssPageName=STRK:MEAFB:IT

     TIA,
   Judith