This is the inside of an Aqualink Contoller System for Automated Pool/Spa Controls. They come in 4 sizes – RS4, RS6, RS8 and RS12. The number after the RS tells you how many components it will operate. This particular photo is an RS6, which will operate 6 items all on their own separate relay and control button: (1) Filter Pump, (2) Cleaner Pump, (3) Booster Pump, (4) Blower, (5) Pool Lights, and (6) Spa Light. With an RS8, one can add 2 more items onto relays and each item is controlled separately. An RS12 is for huge projects with Water Features, Sheer Decent Water Fall, Step Lights, Yard Lights, etc.