This is the "Ring" version of this effect.  (It was also released in a version that used replicas of 45 rpm records, instead of rings).   The Ring version was made in three different colors -- yellow, red and green.  This set is Yellow.    So in this one, black rings change to yellow.

Three black flat flexible plastic rings are shown on both sides and one by one, they change to yellow.  This effect reminds me of some of Pavel's colorful effects with rings.  There is no additional cover -- the rings are counted and shown to be black and then one by one change to yellow as you continue to count them.    The changes are visual and magical, though you will also have to practice this one -- it is not "self-working".

The rings are made of flexible but sturdy plastic.   It is a very high quality set of props.

This item as a hard-to-find collectible, which should be of interest to any serious collector of Tenyo, Tricks Co and other Japanese magic from the 1970's.     Don't miss this rare item.

CONDITION NOTES:  previously owned, but apparently unused,  Opened but complete with all props as issued.  The instructions appear to be a photocopy of the original instructions.   No original package, which was simply a cello bag.