The Weathermatic SLDEC4 Valve Decoder 4 Station Decodes signals from the SLM48DM to open and close valves. It is shock resistant and has built in surge protection. It is fully programmable for valves addresses using the SLM48DM. Weathermatic products are designed with efficiency in mind. The typical Â½-acre commercial property uses about one million gallons of landscape water per year. On average, properties exceed the landscape watering need by about 38% - or 380,000 gallons.