Sol Republic has just taken the wrapper off its latest in-ear headphones, which it's calling the first "cross-over" earbuds because it's designed for both fitness buffs and the everyday commuter. It offers a "FreeFlex" technology that promises a secure, universal fit in any ear due to an adjustable ring around the ear tip, and it's also water- and sweat-resistant for those of you who like running in the rain. As you might expect, there are also volume controls, a microphone and a button that'll let you answer calls or switch tracks. As for sound quality, Sol Republic says the Relays are powered by a new I5 Sound Engine that "delivers full sound with balance and details that bring out the best in any type of music." Just like all other Sol Republic headphones, the ear tips, which come in four different sizes, are replaceable for life. The Relays are available now in black for $79.99 at Verizon stores and the company's website, and the whole color gamut -- black, white, Horizon Blue and Lemon Lime -- will arrive in nationwide retailers some time in February 2014.