Huawei Honor Band 4 and Band 3 Pro appear with heartrate, color screens - CNET
Huawei Band 4 ADS-B29 Graphite Black Smartwatch
Amazon.com: Bands Compatible with Huawei Band 4 & Huawei Honor Band 5i Band Soft Silicone Waterproof Adjustable Sport Watch Strap Replacement Wristbands for Huawei Band 4 Smartwatch Band Accessories (10Colors) : Cell
Wearfit App|huawei Band 4 Pro Smartwatch - Gps, Heart Rate, Waterproof, Oled Screen
User manual Huawei Band 4 (English - 30 pages)
Wearfit App|huawei Band 4 Pro Smartwatch - Gps, Heart Rate, Waterproof, Oled Screen