(NEXSTAR) — What do New York Jets quarterback Aaron Rodgers and Indianapolis Colts quarterback Joe Flacco have in common? In addition to being among the oldest active players in the NFL, alongside Jets punter Thomas Morstead and Tennessee Titans kicker Nick Folk, they may stick out to an eagle-eyed football watcher.  Why, you may ask? It’s not for their specific roles. Instead, take a look at their helmets.  In the slideshow below, you can see all four players wearing similarly-shaped helmets. You may even notice how different Morstead’s helmet looks compared to that of his teammate, kicker Austin Seibert. New York Jets kicker Austin Seibert (15) is congratulated by Thomas Morstead after kicking a field goal during the second half of a preseason NFL football game against the Carolina Panthers, Saturday, Aug. 17, 2024, in Charlotte, N.C. (AP Photo/Mike Stewart)Indianapolis Colts quarterback Joe Flacco (15) warms up on the field before an NFL football game against the Buffalo Bills, Sunday, Nov. 10, 2024, in Indianapolis. The Bills defeated the Colts 30-20. (AP Photo/Zach Bolinger)Tennessee Titans place kicker Nick Folk on the sideline during the first half of an NFL football game against the Detroit Lions, Sunday, Oct. 27, 2024, in Detroit. (AP Photo/Carlos Osorio)New York Jets quarterback Aaron Rodgers (8) passes the ball during an NFL football game against the Houston Texans Thursday, Oct. 31, 2024, in East Rutherford, N.J. (AP Photo/Adam Hunger) Unlike their pants and other parts of their uniforms, NFL players do get to choose which helmet they wear — as long as it meets guidelines set by the league. In April, the NFL, in partnership with the NFL Players Association, approved 12 new helmet models for players to wear during the 2024-25 season. Roughly 20 total helmets were ranked based on laboratory performance and considered recommended models by the league. Three models, however, were considered “not recommended” because of their “poorer laboratory performance.” These helmets are prohibited for new players and those who did not wear them in 2023. Why some NFL helmets may look different this season Among the models limited to certain players is the Schutt Air XP Pro Q11 LTD — the helmet Rodgers, Morstead, Folk, and Flacco are said to wear. The helmets also closely resemble those the players wore in college and early in their NFL careers. Southern California's Lawrence Jackson sacks California's quarterback Aaron Rodgers during the first half in Los Angles on Saturday, Oct. 9, 2004. USC won 23-17. (AP Photo/Chris Carlson)** FILE ** In this Jan. 26, 2008 file photo, North Team quarterback Joe Flacco, of Delaware, looks for a receiver during the first half of the Senior Bowl football game at Ladd-Peebles Stadium in Mobile, Ala. Flacco is a top prospect in the upcoming 2008 NFL football draft on Saturday, April 26, 2008. (AP Photo/Dave Martin, File)TCU safety Colin Jones (28), right, blocks a punt by SMU Thomas Morstead (15) in the first quarter of their football game in Fort Worth, Texas, Saturday, Sept. 22, 2007. (AP Photo/Donna McWilliam)Dallas Cowboys holder Mat McBriar (1) looks on as kicker Nick Folk (6) signals "good" after Folk kicked a 52-yard field goal in the first half of an NFL pre-season football game against the Denver Broncos in Irving, Texas, Saturday, Aug. 18, 2007. The Cowboys won, 31-20. (AP Photo/Tony Gutierrez) Rodgers has already had to change his helmet multiple times in his career. In 2019, his helmet was deemed unusable by the NFL. He told reporters at the time that he had “worn very similar helmets my entire career,” changing only after suffering a pair of concussions, and that picking a new option would not be difficult. That same year, then-Oakland Raiders wide receiver Antonio Brown threatened to retire after the NFL banned his helmet, the Schutt Air Advantage, because it failed to meet the necessary safety standards. (He would later settle on an acceptable helmet, SI reports.) Why are some NFL players wearing two mouth guards? It’s too soon to say whether Rodgers, Morstead, Folk, and Flacco will be grandfathered into wearing their same helmets again next year. Curious which helmet ranks among the best on the NFL’s rankings? The VICIS ZERO2 — the same helmet that went viral in January after the one Kansas City Chiefs quarterback Patrick Mahomes was wearing shattered during the fourth-coldest game in NFL history. KANSAS CITY, MISSOURI - JANUARY 13: Patrick Mahomes #15 of the Kansas City Chiefs heads to the sideline after his helmet was cracked during the third quarter in the AFC Wild Card Playoffs against the Miami Dolphins at GEHA Field at Arrowhead Stadium on January 13, 2024 in Kansas City, Missouri. (Photo by David Eulitt/Getty Images) While we’re talking about Mahomes, have you ever noticed how different his helmet looks? That is also intentional — his helmet is designed specifically to help reduce the impact of head-to-ground collisions, which is the most common cause of concussions among quarterbacks, ESPN reports. You may even notice some other unique helmets, seemingly covered in extra padding, this season: the NFL has approved the use of Guardian caps during games.  During the 2023 season, the NFL recorded more than 200 concussions during the preseason and regular season.