This Unit Will Not Work With The Ttu-1D-X Series (Rechargeable Battery) Ticket Window Units Rect 6.0 (1.9 GHz) technology Voice Tube microphone Monaural style Ensure call privacy with 64-Bit encryption Extended hands-free talk time up to 10 full hours Roam up to 300' from your TTU unit Over-the-head, comfortable design for all-day use Premium audio ensures quality customer communications 2.5 oz Headset weight Battery recharge time 1 hour for 5 hours talk time 3 hours for 100% charge Unlimited user density (Subject to range degradation and environmental conditions).