Complete ISDN Data and Voice Testing, from Line Termination to Terminal Equipment * Used for Prequalifying a Line as ISDN-Capable Through Post-Installation Troubleshooting * Tests S/T and U Interfaces * Operation Modes: NT1-TE, TE and LT/Dry Loop * Single B Channel or Dual B Channel BERT * Automated Call-Yourself BERT * FEBE/NEBE Testing * Embedded Operations Channel * 64K and 56K Data and Voice Calls * Amplified Speaker Transmitter Mute Switch * On-Line Assist Key Explaining Complex Messages in Plain English * 20 Location, 19 Digit Repertory Dialer * Redial * Backlit LCD Display * Backlit Keypad Operates on 4 AA Alkaline or Rechargeable NiCad Batteries * DropSafe (TM) Impace Resistant * 12 VDC Vehicle Adaptor/Charger * A/C Wall Adaptor/Charger * Rainsafe (TM) Water Resistant , 40kHz Tone Generation (U Interface) * 96 kHz Tone Generation (S/T INterface) * Weight: 2.5 lbs * User-Upgradeable Software via PC Serial Port * Field-Replaceable Spring Loaded Belt Clip * Self-Tests with Internal Diagnostics for Trouble-Free Operation * Lightweight, Ergonomic/design * TS250 Basic Rate ISDN Test Set with ABN, RJ45 Cord.