FiiO SK-M21C Cassette-Style Protective Case for M21 Color:Blue the K3 is equipped with

the K3 is equipped with both 3

M17 PORTABLE DESKTOP-CLASS PLAYER

it completely works which is what it is made for in the first place

Compatibilty

it is necessary to affix some kind of protective film to the inner aspect of headphones from this series

FiiO SK-M21C Cassette-Style Protective Case for M21 Color:Blue the K3 is equipped withSK M21C Cassette Style Case for M21 Two colors available Retro cassette shape Contact linkage Magnetic opening and closing Inner padding Start your retro musical journey with the M21 A retro cassette style case custom made for the M21, with precisely cut openings and a perfect fit. The case are made of specially selected high toughness and polycarbonate materials, high transparency giving it a pure, attractive look while making it light and portable.