All points of the track should be equidistant from this point. Measure the total distance from one side of the track to the other through the negative axis point. This is the track diameter. The second generation TEC TEC 2 is a small solid particle that has been added into the reactive urethane shell material. These particles are smaller and softer than the original TEC with sharper edges to bite through the oil.
Smaller particles means more contact points on the lane.
The TEC 2 particles are mixed throughout the entire shell. With time, the sharp edges will wear smooth. Sanding or resurfacing will restore the sharp edges. The TEC 2 shell can be resurfaced easier than TEC because these particles are softer than TEC's glass microballoons. Sanding exposes new particles below the surface of the ball with fresh, sharp edges.