This 2 pack of connectors with wire leads plugs directly into Thunder Power balancers and chargers. The wire leads can be spliced onto the balancing leads of any brand of 14.8 volt (4 cell) or 18.5 volt (5 cell) Lithium Polymer battery pack. Be sure to check the polarity before splicing. Incorrect polarity may cause permanent damage to the charger or balancer and may cause a fire.