The Nordic Track 4 lb Weighted Toning Ball is a versatile exercise ball designed for both yoga and strength training. Made of durable polyvinyl chloride (PVC) material, this blue ball is perfect for full-body workouts and can be used for both indoor and outdoor activities. With its compact 5-inch size and 4 lb weight, this toning ball from NordicTrack is ideal for home use by adults looking to enhance their gym and training routines.