The function of a safety rope is to prevent the loss of headphones during exerciseip: The new version of?LP40 is higher than the previous version of LP40, with a higher Bluetooth level, a larger battery capacity, and a comprehensive upgrade of performance. We have added the product to the shelf. Welcome to buy2021 new Lenovo LP40 gaming headset headsetScopeOverviewBT 5.1 technology provides high-speed data transfer rate, stable performance and low power consumption. With T W S technology, you can use headphones individually or in pairs. Equipped with a 350mAh charging box, which can store and charge the headset. The built-in microphone provides clearer and more realistic sound. It will bring you a perfect user experience.Brand Name: LenovoModel: LP40BT version: 5.1Transmission range: up to 10m (without obstacles)Unit diameter: 13mmFrequency range: 20-20KHzSpeaker sensitivity: 98dBMicrophone sensitivity: -32dB?3dBImpedance: 32?Charging box battery capacity: 3.7V 350mAhHeadphone battery capacity (each): 3.7V 40mAhMusic playback time: about 3 hours (depending on the volume of the music)Color: black, white (optional)Headphone weight (each): 3.2g / 0.11ozPacking size: 8.7*8.7*2.8cm/3.42*3.42*1.10ozPackage weight: 64g / 2.25ozLenovo LP40 gaming headset headsetOverviewBT 5.0 technology provides high-speed data transmission speed, stable performance and low power consumption. With T W S technology, you can use headphones individually or in pairs. Equipped with a 230 mAh charging box, which can charge the headset. The built-in microphone provides clearer and more realistic sound. It will bring you a perfect user experience.ScopeBrand Name: LenovoModel: LP40BT version: 5.0Transmission range: up to 10m (without obstacles)Unit diameter: 13mmFrequency range: 20-20KHzSpeaker sensitivity: 98dBMicrophone sensitivity: -32dB?3dBImpedance: 32?Charging box battery capacity: 3.7V 230mAhHeadphone battery capacity (each): 3.7V 40mAhMusic playback time: about 3 hours (depending on the volume of the music)Color: black, white (optional)Headphone weight (each): 3.2g / 0.11ozPacking size: 8.7*8.7*2.8cm/3.42*3.42*1.10ozPackage weight: 64g / 2.25ozpacking list1 * A pair of earplugs1 * Charging box1*charging cable1 * User Manual (English/Chinese)