The Weller 7770 Standard Series Modular Soldering Iron Handle is for SL325, SL335, SL345, and SL500 and is 2-wire ungrounded. The modular soldering irons utilize interchangeable handles and has interchangeable heaters and tips for custom applications and maintenance. The Weller 7770 Standard Series Modular Soldering Iron Handle has a 5ft cord and features cool, soft touch, acid, and flux resistant grips.