Features: Ergonomic Design: Adjustable headband length, soft ear cushion for maximum wearing comfort, suitable for different head size wearing. Multi-purpose Headphones: Fits for making office business conference calls, call center phone calls, speech dictation, online courses, language learning, etc. Noise Canceling Microphone: Built-in noise-canceling rotatable microphone can block out unwanted background noise for precise voice picks-up, ideal for clear conversation. Wide Compatibility: USB plug and play, no external power or drive needed. Compatible with desktop computers, laptops and other USB o devices. In-line Control: With in-line control, you can easily control volume up and down, mute mic and mute speaker. Specifications: Model Number: OY359 Drive Unit: 40mm Rated Power: 20mW Operating Voltage: 3.7V Working Current: 0.3-1A Mic Size: 5.7mm*5.2mm±0.5 Mic Sensitivity: -36dB±3dB Directivity: Omnidirectional Frequency Range: 20-20KHz Sensitivity: 103±5dB Impedance: 32Ω±10% Input Plug: USB Plug Color: Black Cable Length: 1.8m±0.2m Main Item Weight: 146g/5.15oz Package Size: 17.7*14.5*7.2cm/6.96*5.70*2.83in Package Weight: 187g/6.59oz Package List: 1 * USB Headset