The TF4 is a super-strong fixed-cheek folding stock with a solid hinge lockup. When the stocks are folded, they are held together by a very basic, reliable locking system. The system uses a standard flush cup on the left side of the stock and a push button on the right side. The TF4 comes with standard shell but may be upgraded to 100% carbon fiber Elite Tac Shell. Average weight is 3.7 lbs with standard shell and 2.7 lbs with Elite Tac shell.