Corning fiber and cladding Standard zip cord jacketing, OFNR Green connectors are on ends with angle polish for decreased return loss APC and UPC ends 100% inspected and tested for correct return loss and insertion loss levels LC/UPC to SC/APC Corning fiber and cladding. Standard zip cord jacketing. OFNR Green connectors are on ends with angle polish for decreased return loss. APC and UPC ends 100% inspected and tested for correct return loss and insertion loss levels.