pass [SEP] let me start with the fact i bought this for the roller the roller is plastic not metal as generally indicated also the two balls roll inward and pinch the skin it is painful on the face cheeks particularly i think i will like it to massage out tight muscles on my shoulders but it is not going to work for the intended purpose at all the jaw exercisers these were a bonus i m not sure how much i ll use them in fact i already have this exact set going unused that i got for free another time all around i m disappointed in this purchase