Backstreet's back . . . and hotter than ever? The Backstreet Boys released a 30-second teaser for their new "Show 'Em (What You're Made Of)" music video, and it looks like the boy band is now made of muscle!

Reminiscent of the old videos for their chart-topping hits in the '90s, the Backstreet Boys -- Brian Littrell, Nick Carter, A.J. McLean, Howie Dorough and Kevin Richardson -- sing passionately into the camera while scantily clad. Both Littrell, 38, and McLean, 35, go shirtless, showing off their toned bodies and rock-hard abs. Dorough, 40, and Richardson, 42, however, style tight black T-shirts, and Carter, 33, wears a black tank top.

"When walls starts to close in/ Your heart is frozen over/ Just show 'em what you're made of," the group sings. "When sun light is fading/ The world will be waiting for you/ Just show 'em what you're made of."

"This song is very personal and special to us," the band wrote on their Facebook page. "We hope you love it as much as we do." 

"Show 'Em (What You're Made Of)" is the second worldwide single from the Backstreet Boys' eight studio album, In a World Like This. 

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Watch the teaser video above and tell Us what you think!