Features: 6 Big technological breakthroughs, no pressure sensation while sleep on the side, lightweight design, comfortable and close to the ear. Second generation acoustic chamber+digital enhancement technology, lossless sound quality, stereo sound. Fast speed BLE5.3 chip, low power consumption, stable connection without disconnection. Type C charging port, 58H battery service life, enjoy music. Intelligent digital display, real-time display of battery statues, knowing the charging compartment situation . Specifications: Material: Plastic Color: white, black, skin color(optional) Size: about 5.7x3.7x2.4cm/2.24x1.45x0.94inch Name: M51 Sleep Earphone Bluetooth-compatible version: V5.3 Standby time: 100 days+ Charging cycle of the charging compartment: 4 times+ Earphone battery capacity: 30mA Product chip: Lanxun solution 5656C2 Bluetooth-compatible distance: 10-15m Working hours: 3-4hrs Charging time: approximately 1.5hrs Charging compartment battery capacity: 250mA Battery service life: about 58hrs Note: Please allow 1-2cm errors due to manual measurement. Please allow for slight color differences due to different display resolution. Package includes: 1 Pair In Ear Earphones