The YY Vertical Climbing Mug is designed to enhance your training routine by challenging your grip strength, making your fingers as strong as your biceps. This unique training mug set includes three different cups, allowing you to tailor your workout to your specific needs and seamlessly switch between exertion and relaxation phases. Please note that these mugs are not microwave-safe. Designed to enhance grip strength and finger muscles Includes three distinct cups for varied training Perfect for alternating between effort and rest phases Not suitable for microwave Dimensions 8.2 x 9.6 cm Volume: 300 ml