GREAT FOR TRAINING & 1-YEAR WARRANTY: 30 days money back & 12 months worry-free guarantee. Use in office and call center training with your training headset, both users can simultaneously listen & talk into one conversion via this adapter. You can enhance the training experience by mentoring new employees in real time. EASY TO USE: Plug and Play, simply connect the two plantronics headsets and computer with USB QD adapter or telephones with Plantronics QD Polaris Cable to the training splitter adapter. Allows the use of two headsets to one device, making it ideal for training sessions. DURABILITY & LENGTH: Straight Cable Length 4.4 feet(135cm). Professional design and quality materials make this training adapter for Plantronics QD headset more durable and stronger, hard to damage, perfect for Monitoring, Call Center, telephone marketing training. SIMPLE AUDIO CONTROLS: This training adapter comes with professional in-line mute switch (lock mute) & volume controls. Quick Disconnect attaches to two Plantronics Headsets. Both headsets can listen and talk, and the toggle switch allows the supervisor to mute one of microphones. COMPATIBLE QD TYPE: The Training adapter QD Y Splitter Cable compatible with all Plantronics quick disconnect headsets, such as H251, H251N, H261, H261N, HW291N, HW301N, HW710, HW720, and all H-series & all HW-series and same style QD like TruVoice/VoiceJoy/Daily QD headset. NOT for Jabra GN, Yealink, MAIRDI, Sennheiser EPOS headsets.