Long® 300mg/10ml (B-Tren-Test-Mast-Long®) is a combination product containing esters of testosterone, trenbolone, and masteron in one injection. It is used to help build muscle, strength and size. It helps athletes to train harder and increase endurance. The long-acting esters of testosterone and trenbolone ensure that testosterone and trenbolone levels remain elevated for extended periods. Masteron is added as a cutting agent to promote fat loss.