Viavi TRI-ISTOP-1250MHZ I-Stop Reverse Test Probe, 1.25 GHz 971825 Genuine VIAVI (formerly JDSU) RF test accessory, rated DC to 1.25 GHz . Precision i-Stop reverse test probe with N-type male and female connectors , used in RF, telecom, and cable testing applications. Includes: x1 I-Stop Reverse Test Probe For any questions, you may contact us via the eBay messaging system.