The OPTOKON OLCF62 is designed for OTDR measurement, it combines to devices: OTDR launch cable and filter 1625 nm.
The Launch cable is recommended for measurement of optical trace with OTDR, as described Launch cable datasheet, see document: TEQ_05-11_EN-OLC-M_P.
By the help of filter 1625 nm and OTDR equipped with laser source 1625 nm the testing of “live” optical fibers is possible without traffic interruption.