A great addition for your 12 Wide Silent Runner Wheel! The perforated design of the AutoClean Track allows feces urine and other pet debris to drain from the wheel. This track requires much less cleaning than other solid-surfaced tracks and increases ventilation within the wheel. *THIS IS ONLY A TRACK WHEEL SOLD SEPARATELY* ASSEMBLY INSTRUCTIONS: Remove the standard running track on your Silent Runner wheel. Begin by inserting the corner of the AutoClean Track into the molded edges of the back panel (black) for the Silent Runner wheel. Once the corner edge is pushed in begin working the AutoClean Track all the way around the wheel into the groove. Once completely in the groove push the clear connector into place connecting both ends of the track. Set the front wheel panel on the AutoClean Track and starting with the side away from the connector work one small section of the sandy track into the front wheel panel groove (panel with the openings). Once a small section of the track is in the groove apply pressure (squeeze down) all the way around the wheel until the track is in place. You may need to push the last section near the clear connector in with your fingers. Set the wheel down on a hard flat surface and apply pressure all the way around the wheel to secure the track in place.