This mode conditioning fiber optic cable is made with Corning glass fiber and consists of 2 simplex ST male on one end and 2 simplex ST male on the other end. It allows you toconnect singlemode equipment such as, gigabit routers and switches, to existingmultimode cable environments. It does so by emulating a LED light sourcefrom a laser light source by off-setting the fusion splice of the singlemodeleg onto the multimode cable. They are typically purchased in pairs (onefor each end of the cable run) and used in multimode cable runs over300m. The singlemode cable leg is connected to transmit on the equipmentend.