The Fluke Network 52801004 TS52 Pro Test Set with 346A Plug features the latest in test set technology. Designed with a superior, radiant liquid crystal display (LCD) user interface, it allows you to see what cannot be heard in any outside plant environment. The back lit LCD and phosphorescent (glow-in-the-dark) keypad brings light to even the darkest of work environments, providing perfect line diagnostic clarity. The TS 52 PRO Test Set is also equipped with 2-Way Speakerphone and DataSafe Pro data protection technology featuring superior high-impedance monitoring, Data Lockout and Lockout Override, making you completely safe.