Convert any irrigation controller to two-wire operation with Underhill's 2Wire Decoder System. The Universal Decoder Module can be mounted inside an existing controller or externally up to 3,000 feet from the controller. The 2Wire System is designed for mid-to large-sized irrigation sites and controls up to 63 stations. It can be retrofitted to existing systems. Station numbers can be programmed in the field or the shop by a push-button programmer.