Our NC36 headset is a high-performance headset implemented with active noise reduction (ANC) function. Its head hoop structure allows long-time wear without discomfort. Weight: 56 g/ 2 ozNoise Reduction Ratio (NRR): 36+ dB (at low frequencies) Battery: Li-Polymer rechargeable battery (One charge can last 8 hours) The accessories include 3 pairs of ear tips: small, medium, and large. The user should select the right size for maximum noise reduction. SHIPPING: 4-6 business days