Muscletech over the years have made a number of shakers available to fans. There latest one is the first time they have gone with a compartment product. The 20oz semi transparent bottle uses a distinctive dome lid, removable non-grill strainer
and is made of a high density BPA free plastic. The shaker comes with a SmartShake like screw on compartment for powders ranging from pre-workouts to proteins. It measures about half the 20oz bottle so there is a good chance it also has room for some mass gainers.