Rain Bird SRK Replacement Solenoid for APAS/ASVF/ECV/CP/CPF Series Valves. The SRK solenoid replacement is designed to replace solenoids on 3/4-in or 1-in Rain Bird valves. Compatible with: APAS; ASVF; ECV; CP; CPF models. Important note: Replaces only newer hexagon shape solenoids; will not work on older round solenoids with ridges. Energy efficient, low power encapsulated solenoid with captured plunger for long-lasting dependability. Easy to remove and install. Rain Bird “The Intelligent Use of Water”