Aerobie

An Aerobie is a flying ring used in a manner similar to a Frisbee, for recreational catches between two or more individuals. The Aerobie differs from a Frisbee, however, in that it is a ring rather then a disc, and has exceptional stability. Also, since it has much less drag than a frisbee, it can easily be thrown several times farther than a frisbee. It holds the Guinness World Record for the "longest throw of an object without any velocity-aiding feature". The record was originally set in 1986 and then broken in 2003 in San Francisco by Erin Hemmings. The 2003 record toss traveled 1,333 feet (406.3 metres) and the Aerobie was airborne for over 30 seconds.

Designed in 1984 by Stanford scientist Alan Adler, the Aerobie has a polycarbonate core with soft rubber molded onto the inner and outer rims. The outer rim has a spoiler designed to impart stability. The AEROBIE® is available in two sizes. The AEROBIE® PRO RING is 13" in diameter, while the AEROBIE® SPRINT RING is 10" in diameter and is the best model for younger throwers or when your throwing space is tight.

Other Aerobie models include a triangular boomerang and smaller discs marketed at kids and dogs.

Reference

Paper authored by the inventor Alan Adler, explaining the design considerations.