Based upon internal testing and customer response these are the highest quality & best performing large resistance soldering handpiece available on the market today. Specifications: Please adhere to 50% Duty Cycle Length 10"(25.4cm), 10ft (3.05m) Connects to Power Unit via Ring Terminals Replacement Electrodes: Model # 10565 Model # 10566 Included in Systems: 10505 - Industrial Capacity Plier-Style Resistance Soldering System 10557 - Medium-Duty Resistance Soldering Plumbing System 10577 - Heavy-Duty Resistance Soldering Plumbing System.