Feature: 1. Use the most advanced Bluetooth 5.0 technology. Provides call stereo sound. Fast and stable transmission. 2. Lossless rendering technique, offers truly natural, authentic sound and powerful subwoofer performance. 3. Adopt ergonomic and in‑ear design, reduce noise ear cap bring safety fit, will not harm your ears, let wearing experience comfortable. 4. 9D sound multi‑dimensional sound quality. True wireless earplugs can block out ambient noise and avoid wind noise during running, cycling, jogging, etc. 5. The mini charge box has a large capacity, automatic charging when put in the earphones. Lithium battery to protect your wireless music. Specification: Item Type: Bluetooth Earphone Material: ABS Color: As Pictures Shown Weight: Approx. 66g/2.3ozProduct Model: L21pro Bluetooth Version: V5.0+EDR Support Protocol: SPP/A2DP/AVRCP/GAVDP/HID/AVDTP/AVCTP/IOP/HFP/RFCOMM SNR: 90dB Sensitivity: 90.5dB Transfer Distance: 10-15m/32.8-49.2ft Control Mode: Press Button Battery Type: Polymer Battery Earphone Battery Capacity and Model: 50mAh/501015 Charging Box Capacity and Model: 300mAh/602030 Running Time: 4 Hours Earphone Charging Time: 1 Hour Charging Box Charging Time: 1 Hour Horn: Φ8 32Ω Audio Range: 20HZ-20KHZ Channel: True Stereo (True Wireless) Distortion: <1%. Package List: 1 x Charging Box2 x Earphone4 x Ear Cap1 x Charging Cable 1 x Manual