Pro Line 10113 17 2.2 3.0 Prime Short Course Truck or Buggy Tires MC Clay Compound Chesapeake & Ohio This gives the system four This gives the system four sensor pairs for use on four tracks in one direction or two tracks in both directions (or any other combination of the four sensor pairs such as a center bi directional track with the outer tracks being single directional on a three track railroad) die cast frog with a power contact to optionally energize the frog and prevent loss of power when a locomotive is passing through eliminating the need for traditional treaded tires The raised treaded portion of the Prime tire has a distinctive rough surface texture similar to a ground “slick” tire and makes the Prime tire have the maximum performance right out of the package