The WS1TC has been upgraded to have a four-digit LCD display with status indicators for a more user-friendly status appearance and for programming. This valve has a new, high-performance, compact surface mount optical encoder for better drive accuracy. Clack has also added a three-volt lithium coin cell battery that is designed to upkeep the time of day for up to eight hours in the event of power outages. The new TC control now detects 50/60-Hz line frequency, and will also set the 12/24-hour time, keeping formats automatically. http://www.clackcorp.com, (608) 846-3010