Thank you for viewing. The YYK-520 is an ultra-lightweight, ergonomic wireless business headset. I purchased it new on Amazon, but I'm selling it because I hardly used it. I have confirmed that it works perfectly, but the outer box is not included. I only paired it once for testing, so it's in very good condition, but there might be something I overlooked. Please only purchase if you understand that it is a used item. - Model Name: YYK-520 - Wireless Version: V5.3-EDR - Design: Ergonomic design - Weight: Ultra-lightweight - Charging Time: Approximately 1.5 hours - Operating Temperature: -10 to 40°C - Standby Time: Approximately 150 hours - Continuous Talk Time: Approximately 12 hours - Compatibility: A2DP/HFP/HSP/AVRCP/EDR