The Synchro Cord For Flash Meter from Sekonic is a specially designed "T" style PC cord (3 leads) allowing for easy flash connections between the meter, camera, and flash unit. Its extra long, 5m (15 foot) length is compatible with all Sekonic Flash Meters. One male lead connects to your light meter. The second male lead goes into your camera. The third lead is female and connects with your flash but requires an optional male-male lead.