This is a good mass builder for the forearms, and is simply a two-handed version of the old classic lever bar lift. The user can "choke up" on the bar at the beginning of a set in order to do a few warm-up reps, and then progressively move has hands out toward the far end of each handle to do the working reps. This positioning of the hands on the bar has a huge effect on the resistance generated, since the leverage becomes less favorable the further out your hands are placed. As the lifter approaches muscle failure at the end of a set, he/she may then choke up on the handle bars again to lower the resistance. The effect is that of a drop set, as if the weight was progressively lowered. The technique produces incredible intensity (resulting in incredible progress). 

It is important that the arms are kept pointing straight down, and the elbows are kept almost straight, just slightly less than locked. Focus on keeping the movement centered on the wrists as much as possible. bring the bar from the floor to the top position in a controlled, smooth, steady manner - avoid jerky movements and momentum. Hold the bar for a second or two at the top position, then lower it back to the floor in a controlled manner. Don't just let it fall, try to drop it over a period of several seconds. It is this steady tension on the forearms that will produce results; form is important here. Don't sacrifice form for heavier weights - many beginners start with just the empty bar and move up in small increments from there.

Statically holding the bar at the middle position for a count of 10 on each rep can be a real strength builder. The bar is being used without weight plates so the view is not obscured.