Compared to other electronics, the earbuds are low power products. Hence for charging safety, please make sure the charging current is no greater than 5V 1A. Please do not use fast charger. Long term use an inappropriate adapter to charge will damage the case. If the case and earbuds are damaged by using an improper adapter, this kind of man-made damage is not covered by the warranty. Description Features: 【Innovative Design & Comfortable Fit】 Laser-engraved leather texture combined with metal elements achieves a balance between exquisite and comfort. The ergonomic design with each earbud weighing only 0.14oz provides a perfect wearing experience with all-day comfort. 【Long Battery Life & USB-C Charge】 8 hours playtime per charge and another 2.8 recharges by the charging case. The Free2 classic wireless earbuds extend your enjoyment to 30 hours in total. It only takes 1-2 hours to charge the earbuds and the charging case by the convenient USB-C charge. 【Superior Sound & Reliable Transmission】 6mm dynamic driver presents strong bass, mellow mids, and clear vocals to let you enjoy the immersive beating notes. The Bluetooth 5.1 ensures a stable connection and helps enhance the sound to be more pleasant for your weekly workout and leisure time. 【Smooth Calls & Easy Touch Control】 The mics are equipped with dust-proof metal mesh to reduce wind noises interruption and make the calls clear and smooth. The effortless on-ear touch control allows your access to control volume, switch songs, pause/answer calls, and activate voice assistant. 【Single/Twin & IPX5-Rated】 Instant pairing right after out of charging case and seamless connection between single and twin mode for you to use one earbud only or both together easily. With the IPX5-rated, the Free2 classic earbuds are perfect for your daily light exercise. Specification: 1.Sensitivity: 109 ± 3dB 2.Resistance: 16Ω±15%Ω 3.Frequency response range: 20-20000Hz 4.Codecs: SBC 5.Active noise cancellation: No 6.Bluetooth version: Bluetooth 5.1 7.Bluetooth Prole: HFP 、 A2DP、AVRCP 8.Bluetooth chipset: 6973D4 9.Max working range: 33ft / 10m (without obstacle) 10.Play time: about 8 hours (60% volume) 11.Earbuds charging time: about 1.5 hours 12.Charging case charging time: about 2 hours 13.Earbuds recharge: About 2.8 times 14.Earbuds power capacity: 3.7V / 86mAh (43mAh * 2) 15.Charging case power capacity: 3.7V / 350mah 16.Earbuds dimension (L * W * H): 25.84*18.58*17.34mm 17.Charging case dimension (L * W * H): 63.1*44.3*27.1 Package included: 1.2x SoundPEATS Free2 Classic Wireless Earbuds 2.1x Type-C Charging Cable 3.1x charging case 4.1x User Manual 5.6x Various Eartips