LokSound by ESU Wheel Wipers - Current Collectors for Electrical Pickup are easy to install electrical pickups for passenger cars and cabooses with interior lighting. Simply glue them to the underside of the truck so the pre-tensioned contact strips touch the inside of the wheels or flange. Use one set per axle is enough. The connecting board has a soldering pad for easy wire connection. Suitable for any axle on HO or N equipment. Wheel Wipers - Current Collectors package includes eight pieces.WARNING: This product can expose you to chemicals, which are known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov