Description Siindoo is a national high-tech enterprise engaged in researching, developing, manufacturing, marketing and service. Products covered ANC headphones, BT headset, TWS earphones, Neck-band earphones etc. Founded in 2008 and headquarted in Shenzhen,China. Factory have certified with ISO9001 & BSCI.All of products are greatly appreciated by customers all over the world. Welcome to share your any ideas with us!! If you need wholesale , please free to contact us for customize 【Active noise cancelling technology】 Reduce Ambient Noises By Up to 90% Our team of engineers conducted more than 100,000 tests in real-life scenarios to fine-tune Siindoo built-in ANC microphones and digital active noise cancellation algorithm. As a result, the hybrid active noise cancellation can detect and cancel out a wider range of low and mid-frequency noises such as cars and airplane engines. 【Comfortable and Foldable Design】 The on-ear Headset are designed for long-term comfort. The soft over-ear pillows have advanced ventilation and a unique ergonomic fit for an individual, fit for every head shape. They are foldable and adjustable, which make sure that the ear is snug around your ears for a better sound experience and immersed in the full sound, and ONLY 0.6lbs lightweight design makes it the best choice for travel, workout and every day use. 【HiFi Stereo Headphones】Adopted most advanced dual 40mm dynamic sound unit , and advanced Bluetooth 5.3 chip , siindoo foldable headphones aim to deliver you superior sound quality with high fidelity deep bass and crystal clear treble, lose yourself in immersive music even in the lowest volume levels! The goal that provide customers with outstanding sound quality is our constant pursuit. 【Bluetooth 5.3 & Built-in Microphone】Built in Bluetooth 5.3 technology, siindoo overhead headphones can offer more stable transmission speed, lower latency and better audio output,which give you wonderful music enjoyment. And built-in microphone of our lightweight headphones enables a hands-free clear phone calls, which like talking face to face with your friends. 【Up to 35 Hours of Playtime】With up to 35 Hours of listening time of siindoo over ear headphones in Bluetooth mode, you'll always have music to inspire you. Come with a 3.5mm audio cable, regardless of whether you want to use wireless headset or wired headphones, siindoo bluetooth headset can satisfy you. Specification: Bluetooth version V5.3 Working distance） ≥10M Charging port：Type-C Battery 400 mAh Charging time about 2.5H Standby time about 132 H Taking time about 30H Music play time BT 35H; BT+ANC about 28H(70% volume) Dual Device Connection Speaker Driver Units Ф40mm Impedance 32Ω±10% Speaker Sensitivity 115dB±3dB Frequency response 20Hz~20KHz Feature: Ergonomic design, more comfortable to wear Active nosie cancelling Lightweight and simple structure Foldable and stretchable design,portable to take Frosted surface texture Stainless steel expandable headband Soft snug leather headband Super music working time CD pattern metal decorative earpad shell+ CNC high aperture High imitation protein material + inert sponge earmuff 3.5mm jack line wired headphone+Bluetooth Fashionable and unique design What's in the box? 1 X siindoo ANC923 Headphone 1 X 0.3m charging cable 1 X 1.2m AUX cable 1 X siindoo bag for gift