With thanks to team photographers and Getty Images, please enjoy photos that have officials in the frame. Note how the officials are carrying their electronic whistles (either tied to their belt loops or tied with a wrist lanyard).
From team photographers (click on a photo to begin gallery):
Michael Banks (Houston Texans)
Note Tony Michalek holding his electronic whistle that is strapped to his belt. (Green Bay Packers)
Perry Paganelli (Minnesota Vikings)
Tom Hill (Seattle Seahawks)
Adrian Hill (New England Patriots)
Bill Vinovich (Green Bay Packers)
Umpire Paul King. Note his electronic whistle. It is strapped to his left wrist and he's carrying it in his hand. (New England Patriots)
Dino Paganelli (New York Jets)
Down judge Mike Carr and side judge Don Willard (Green Bay Packers).
Alex Kemp and Greg Bradley (Detroit Lions)
Bill Vinovich (Green Bay Packers)
Tony Corrente (Dallas Cowboys)
Ron Torbert (Baltimore Ravens)
Jeff Seeman (Green Bay Packers)
Jeff Seeman (Green Bay Packers)
Matt Edwards (Detroit Lions)
Fred Bryan (Kansas City Chiefs)
Blakeman Crew (Kansas City Chiefs)
Walt Coleman, IV (Washington)
Tom Symonette (Indianapolis Colts)
David Meslow (Green Bay Packers)
David Meslow (Green Bay Packers)
Tony Michalek (Green Bay Packers)
Mike Carr (Green Bay Packers)
Rick Patterson (Las Vegas Raiders)
Todd Prukop and Tony Corrente conduct an old-fashioned coin toss (Dallas Cowboys).
Don Willard (Minnesota Vikings)
Mark Hittner (Houston Texans)
Jimmy Russell (Las Vegas Raiders)
Dan Ferrell (Los Angeles Rams)
Fred Bryan (Kansas City Chiefs)
Brad Rogers (Washington)
Perry Paganelli ready to judge a field goal (Green Bay Packers).
Shawn Smith (Buffalo Bills)
From Getty Images:
Referee Adrian Hill
Officials Ron Torbert and James Coleman kneel during the National Anthem. Down Judge Jim Mello is in the background.
Line judge Mark Perlman
Referee Ron Torbert
Down judge Derek Bowers
Referee Shawn Hochuli
Referee Jerome Boger and down judge Julian Mapp.
Side judge Jonah Monroe
Down judge Sarah Thomas
Umpire Ramon George. Note the electronic whistle tied to his belt.