The NA-SEC1 chromax.blue set is an accessory kit for fans and includes three NA-EC1 30-cm extension cables. The 4-pin connectors of the NA-EC1 cables are compatible with both 4-pin PWM and 3-pin fans. If larger cases require more than a 30-cm range, multiple NA-EC1 cables can be combined. Thanks to the blue sleeving, the cables are ideal for projects with clean, focused aesthetics and are a perfect complement for fans from Noctua's chromax product line.