Casti Lindy LH900XW Wireless Active Noise Cancelling Headphones Feature rich hybrid ANC headphones with Bluetooth connectivity Technical details Specifications Design: Over Ear Driver: 40mm Neodymium Active Noise Cancellation: 95% reduction of low frequency noise Bluetooth Standard: 5 Bluetooth Chipset: CSR8670 Battery Type: Internal Lithium Polymer Battery Life: 30Hr ANC Only, 15Hr Wireless Only, 12Hr ANC & Wireless Impedance: 32Ω passive mode / 100Ω ANC mode Sensitivity: (1mW@1kHz ±3dB): Passive 93dB ANC 95dB Frequency Response: 20Hz – 20kHz Nominal THD: Passive