The Self-Serve Relay is an I/O based board devise designed to activate your self-serve timer. It is placed inside your existing coin box or can be mounted in an accessory box. This is a low cost addition that gives you self-serve control at a site, device, and/or user level. You can now integrate self-serve into your monthly pass, self-serve, or individual sales strategy. The self-serve relay is connected via WiFi or wired Ethernet and is activated by scanning a QR code with your cell phone from your car wash branded app.