Test jumper / patchcord with SC/APC to SC/UPC connectors, single-mode fiber (9/125 µm), 20 m length, 1 strand (simplex). Manufacturer lists a corresponding 20 m SC/APC→SC/UPC test cord (TCB-SM-SCA-SCU-20). Distributor/export records specifically reference TJ-B88-91-20M as a 20-meter test jumper, but EXFO does not publish a product page explicitly using the exact MCN TJ-B88-91-20M on the accessories site.