http://tinyurl.com/nhynq7d

Hindawi Adjust Super Vise Gripper Hand Grip Strengthener

84 points of adjustment will insure a strong grip and forearm growth (as long as you use it).

Heavy Knurled aluminum handles for a stable grip.

2,3 or 4 Heavy Duty Springs for building a crushing grip and massive forearms.

45 - 500+ lbs. of pressure, student,men,women can be use it, for all of members from your family.

Included chart depicts 2,3 and 4 springs, you can add the more spring to add to your resistance.