The ADTRAN TSU LT 3rd Generation T1/FT1 DSU/CSU, part number 1203060L1, is a modem card designed for businesses requiring reliable T1 or fractional T1 connectivity. This unit functions as a Data Service Unit/Channel Service Unit, essential for interfacing data terminal equipment with digital lines. It is suitable for organizations that manage their own network infrastructure and need direct control over their T1/FT1 connections. The device features a user-programmable interface accessible via a front panel LCD and keypad, allowing for direct configuration and monitoring without requiring external tools.