Revolution Enterprise's Sweet Loops was the company's answer to finger pain caused by the yo-yo string. The package contained three Sweet Loops and five strings. The back of the packaged explained how to string the finger loop.
Of interest... Over the years yo-yo makers have tried various fittings to alleviate "Yo-Yo Finger" -- the pain caused by prolonged wear of a yo-yo string around your finger. Here are a few variations that have appeared on the market since the early 1980s: