Securely holds and protects most all the latest different sizes and shapes of smaller MP3 players -- everything from a Nomad MuVo to a Rio Cali. It provides quick convenient access to the player because there's no pocket flap; and there's no worry about the player falling out during activity because it is held firmly inside the two neoprene layers of the case by the curvature of the arm. Even if your player comes with an armband strap you'll want your investment to have the extra protection from bumps perspiration and the elements that this carrier provides. Features and benefits - Holds many sizes and shapes of smaller MP3 players phones etc. Maximum width of pocket opening is 7.5 cm. Pocket depth is 6.5 cm. Devices longer than 6.5 cmwill stick out the opening but will still be held firmly inside. No pocket flap so quick convenient access to player Player held firmly inside two neoprene layers by curvature of arm Provides more protection from bumps perspiration and elements than an arm strap Reflective logo patch for nighttime safety Armband size is easily adjustable with one hand up to 52 cm