So,Ive been using this thing for about 3 months every day on top of my usual workout,and I have to say,it has made my grip about 100x stronger and has improved my grappling so much.I feel so explosive , so short message,there cheap,good quality. Buy one. Amazon.com ebay.com any other places sell it with the iso7x. Not looking for sarcasm just trying to help fellow grappler's.