Red® Set Screw EMT Connector 3-1/2″, Steel, Color-Coded
https://nsiindustries.com/product/red-set-screw-emt-connector-3-1-2-steel-color-coded/
Easily identify your connections with Bridgeport’s patented color-coded EMT steel connectors. Use red connectors to join red EMT for emergency circuits, fire alarm and security system applications to an electrical box or enclosure.