The cassette has a rational structure and high capacity. It can be used in telecommunication networks, CATA networks, FTTH, LAN, WAN, etc. The cassette uses an angled polished LC connector with low insertion loss. Inside the cassette is a breakout cable assembly, which uses a Corning fiber in a ribbon configuration for 12 LC connections as the result is connected with 12 LC patch cables on the front of the cassette, and an MTP / MPO 12 UPC connector in the back of the cassette. The cassette can be installed in either vertically or a horizontal MPO cassette holder.