Tablet Headset (Dual-Ear Small Over-Head Type) HS-HP22TBK Specifications Compatible Devices: Smartphones, tablets, and laptops with a 3.5mm 4-pole mini-plug (CTIA standard) ※ Operation is not guaranteed for all smartphones, tablets, and laptops. Interface: φ3.5mm 4-pole mini-plug Cable Length: 1.8m Color: Black Weight: 68g External Dimensions: Width 133 x Depth 50 x Height 164mm (excluding cable) Wearing Style: Dual-ear over-head type Headphone/Speaker System: Dynamic type (stereo) Headphone Driver Unit: 30mm Headphone Maximum Input Power: 30mW Headphone Impedance: 32Ω Headphone Frequency Response: 20～20,000Hz Headphone Volume Control: Yes Microphone Microphone System: Electret condenser type Microphone Arm Length: 120mm Microphone Mute Function: None Microphone Directivity: Omnidirectional Microphone Input Sensitivity: -58dB ±3dB Microphone Impedance: 2.2kΩ Microphone Frequency Response: 100Hz～10,000Hz (From the ELECOM product page) Purchased in 2021, opened once, and connection was confirmed with a Surface Pro 7, but it is unused.