The Galena Century Radio (GCR) A-Runner Radio Structure AW – Kit is the same hardwood and ply sub-base design as our A-Runner Loose Coupler Radio. The side rings are 4 1/2″ in Diameter and will provide a snug fit for a 4” ABS or PVC magnet wire coil. The dimensions of the finished structure are 13 1/2″ W x 7” D x 10 3/4″ H.