LOOK: NFL refs used wrist-mounted horns before whistles

This is an old sports whistle from probably the 1920s or so. Was worn on the wrist and used to call fouls. It has a very cool sound to it. Partial

Antique Wrist Worn Referee Whistle Horn Rawlings MacGREGOR Goldsmith

Whistle while you work, NFL referee style – Football Zebras

Football Referee Whistle. We will provide good quality goods of Japan with good price.

Molten Football Referee Whistle with frip grip VALKEEN RA0030-KS From Japan

Referee knocks over Vikings' Cam Bynum resulting in touchdown

NFL referee appeared to hip-check a player just before throwing controversial, game-changing penalty flag - Yahoo Sports

What are the black string-like things football referees wear on their hands for? - Quora

NFL100: Before they were zebras, they were … candy canes? – Football Zebras

What are the black string-like things football referees wear on their hands for? - Quora

PACKAGE--- 2PCS plastic whistles with lanyards. These whistles are great for referees, coaches, training, teachers, survival, emergency, school, gym,

Whistle, 2 Packs Plastic Sports Whistles with Lanyard, Loud Crisp Sound Whistle Ideal for Coaches, Referees, and Officials