15LBS (600*50*0.5MM) Recommended for beginners, thin legs/arms
20LBS (600*50*0.75MM) is recommended for basic fitness, thin legs/arms
30LBS (600*50*0.9MM) is recommended to have fitness experience, lift kidney and shape
40LBS (600*50*1.1MM) is recommended to have solid fitness experience, strength training
***ll orders will be delivered to you according to your order requirements within 24 hours after placing the order(Orders placed before 5pm ship same day, except Saturdays and Sundays)!