The WINertia TQ(tm) is a WINTERIA (tm) aluminium roller with a new torque coupler. The torque coupler allows the spindle to be mounted more conveniently than the standard spindle aluminum roller. It also allows the operator to replace the shaft without having to purchase the entire roller. It comes in three sizes: 3 x 2 inches. 5 x 2 inches, 6 x 2 inches. Like other WINertia (tm) production lines, TQ can also provide 3D balanced machining processes, which is also Componex's patented design for internal walls. Source: Packaging Expo Titanium Nonstick Double Grill,Nonstick Double Grill,Double Grill Cast Iron Saucepan,Cast Iron Frying Pan Co., Ltd. , http://www.chcookware.com