Hey There!
The Holy Grail of stock traction weights for Magnatraction and Xtraction cars come to us from Sears. I'm not sure of the history here, perhaps some of the historians out there can enlighten us. From a practical stand point, they are a good cheap bet to improve your car's performance.The photo shows the two styles. On the right, the long wheel base only and on the left, the long or short wheelbase version. The two Vipers shown, each require a different type. There is another very subtle difference between the two styles as well. The long wheelbase style weighs 1.8 grams while the variable style weighs about 1.9 grams. The weight on the variable style is also slightly more forward. The choice is up to you.