I thought the hello super twin horns came with a relay?


Cut and pasted description of hella horn kit;
Concentrated, far-reaching sound out of a compact, rugged, all-metal instrument with protective grille. Flat plug connections. Kit contains horns, relay, mounting brackets, and installation instructions.

For cars, trucks, buses and tractors
Voltage: 12V
Frequency: 300 Hz low tone, 500 Hz high tone
Sound level: 118 dB
Connection: Flat plug
Power consumption: Max 72W
Dimensions: 4-27/32" dia. x 3-11/32" depth