Shinwoo's Zan Navi is a multi-style yo-yo with oversized rubber rims, suitable for 1A, 3A, 4A, and 5A. It was sold with a counterweight, but not in the U.S. market, and for a good reason; if it were sold with a counterweight in the U.S., it would have violated Duncan's patent on 5A play. It was perceived by many players to be a Korean equivalent of the Duncan Throw Monkey, which also features rubber rims.