First I cut out a rectangular strip of sheet metal with the same length as the circumference of his ring finger.
Then I soldered the ends of the strip together into a band.
Next I soldered a jump ring onto the band, from which I attached a chain.
Putting that aside I found a rubber bouncy ball and painted it metallic silver and screwed in an eyelet screw.
Once the paint dried I attached the chain to the eyelet. This is a cheap, but decent looking gift for the groom in your life.