The Radiyoactive Fusion was a limited run by Radiyoactive, a small company out of South Africa. The Fusion debuted as the Limited Edition Yo-Yo for the 2006 World Yo-Yo Contest. The yo-yo, molded out of clear plastic, was an update for its predecessor, the Radiyoactive Fission. The Fission was very light, and the Fusion had a lot more rim weight. One downside of the Fusion is that the axle was held in by clear silicone which does not hold it in very tightly, and therefore the yo-yo wobbles uncontrollably.