The Magic-T, a hybrid waveguide junction, that combines an E-plane and H-plane Tee into a single device. 
 
This component is widely used for power splitting, combining, and phase shifting in microwave systems, such as radar and communication networks. 
 
Its "magic" lies in the ability to isolate input signals between ports while ensuring perfect phase balance or cancellation, making it invaluable for high-performance systems.