Purchased on Rakuten (TEAC Store Rakuten Store) on October 1, 2024, and only used a few times (total usage time is less than 10 minutes). KOSS PORTAPRO Type: Open-air Frequency Response: 15 - 25,000Hz Sensitivity (SPL): 101dB 1mW Impedance: 60Ω Total Harmonic Distortion: Less than 0.2% Cable: 1.2m Straight / Dual-sided Connector: 3.5mm Stereo Mini Plug Weight: 60g Accessories: Dedicated carrying case Product Specifications Color: Black Series Name: Portable Series Brand Name: KOSS Manufacturer Model Number: Porta Pro Bluetooth: No Noise Canceling: No Wireless Function: No Wearing Style: Headband Wearing Method: Binaural Representative Color: Black