The fitness circle has an inner diameter of 20 cm and a cross-sectional diameter of 2.8 cm, which is suitable for boys. The fitness ring has a standard installation width. The ring consists of a circular ring, a steel frame and four zippers. The inner diameter of the ring is 20 cm and the diameter of the cross section is 2.8 cm. Hang it on a steel frame with a steel wire rope, and there is a 700-meter belt or canvas belt near the ring to protect the forearm. The distance between the two rings is 50 cm, the height of steel frame is 550 cm, and the distance between steel frames is 300 cm.