MuscleDriver USA Speed Rings will allow you to create a wide variety of training patterns to improve overall fitness, foot speed, coordination, and agility. Using exercises such as directional jumps and high knee fast stepping, you can dramatically increase foot speed and explosive leg strength. Extremely lightweight design allows for convenient transport. Made of durable PVC. Use indoors or outdoors. Set includes a 12, 17" diameter rings (4 of each color red, yellow, and blue), and a custom carrying bag. Weight 2 lbs.