Australian pop rockers 5 Seconds Of Summer first burst onto the music scene as fresh-faced teens back in 2011.
But the quartet looked dramatically different when they arrived at their New York hotel on Thursday.
The boys have all grown up, and showed off their new signature style.
My, have they changed! 5 Seconds Of Summer bandmate Calum Hood is all grown up and looked dramatically different in New York on Thursday, left. He is pictured on the right in November 2013
What a difference: Luke Hemmings has also changed his look over the years, rocking designer wear on Thursday. He is pictured on the right in November 2013
Lead vocalist Luke Hemmings, 21, appeared tired as he exited the group’s chauffeured car and greeted fans.
Sporting an unshaven face and untamed mane of hair, his look was a big contrast to his teenage years.
In the early days, baby-faced Luke sported a shorter quiff-style hairdo and an eye-catching lip ring.
And while T-shirts and baseball caps were part of his old attire, on this occasion Luke rocked a designer leather jacket and shiny leather shoes.
Meanwhile, bassist Calum Hood, 22, cut a very different figure, showing off his elaborate neck tattoo in a light grey singlet top worn underneath a striped shirt.
Gone is his Justin Bieber-inspired hair flip in favour of a rockabilly gelled do’.
Trendy: Ashton Irwin has totally transformed since breaking onto the scene. Picture on Thursday, left, and in April 2014, right
Meanwhile, Ashton Irwin looked all grown up on Thursday, wearing a very stylish ensemble.
The 23-year-old heartthrob was casually chic in a pair of dark jeans, a black T-shirt and designer sunglasses.
The drummer cut a more mature figure compared to his teenage years, when he would often wear ripped jeans and T-shirts.
Big changes: And while Michael Clifford has kept his signature grungy garb, he now rocks several arm tattoos and has dyed his black locks blonde. Michael is pictured on the right in April 2014
And while Michael Clifford, 22, has kept to his signature grungy garb, he now rocks several arm tattoos and has dyed his black locks blonde.
On Thursday, the lead guitarist was spotted in a baggy sleeveless checkered shirt, several bracelets, jeans with multiple pockets and black sneakers.
While the quartet look dramatically different these days compared to their formative years, they have lost none of their ability to entertain fans.
Last month saw 5SOS thrill fans with an acoustic performance in Sydney as part of the Spotify Fans First Event.
Their set included songs from their new album, Youngblood, which was released in mid-June.
The group are currently busy with their Meet You There tour.
Changed looks, same popularity: While the quartet look dramatically different these days compared to their formative years, they have lost none of their ability to entertain fans