The Iron Neck 3.0.

Feel better faster with the leader in neck strength and mobility. Meet the only neck training system with 4-in-1 benefits for recovery, prevention, posture, and mobility. Target and treat muscle imbalances & mobility deficits like never before with the only 360 degree neck and posture trainer. 
Unlike the Pro model, this does not have the variable friction resistance. If you are intending to train rotation with resistance, then consider the Pro model.