The K-Rain 4403-RCW RCW 4000 Series by K-Rain offers a reliable and economical way of automating multiple zoned residential and small commercial wastewater systems. The 4000 line of Irrigation Indexing valves offers a reliable, economical way to automate multiple zoned residential and small commercial irrigation systems. These patented indexing valves allow for the number of watering zones in your spinkler system to be changed quickly and easily. The 4000 valve is available in 4 or 6 outlet models. A quick change of the cam allows the valve to operate with flows as low as 10 GPM and at pressures of 25 to 75 PSI.