Carbon Nanotube Dynamic Drivers Much wider sound stage with higher fidelity. The O7s dynamic are tuned to sound warm and bassy with deep rumbling bass that will smash your brain. Compared to the Dual Balanced version the Dynamic version is like a raging beast ready to roar!   Qualcomm® Chip, Supports SBC, AAC and aptX The MIFO O7 earbuds support SBC, AAC and aptX audio codecs and that makes them ideal for users of iOS and Android devices. The AAC and aptX codecs deliver high-quality audio for better-sounding music. The earbuds also include four separate microphones using Qualcomm’s cVc clear voice technology for making calls.  Machined Aluminum construction Machined aluminum construction achieves beauty and durability that other true wireless earbuds simply can't match. The extra smooth aluminium charging case slips easily in and out of pockets, bags, and storage compartments without risk of damage. IPX7 Waterproof  Waterproof IPX7 nanocoating provides complete protection from rain, sweat, and even full submersion under water. Corrosion resistant coated alumnium refuses to rust or tarnish. Bluetooth 5.0 Bluetooth 5.0 wireless provides up to 20 meters of distance with no distortion and perfectly synchronized zero drop signal. Intelligent Bluetooth pairing means you simply take one or both earbuds out of the charging case to automatically pair to your preferred devices. Independent Usage Independent usage and voice functions with multi-microphone technology. Use one or both earbuds to make and receive calls with tap to control functionality. Tap to adjust music, answer or swap calls, and activate voice commands.