Amazfit GTR Lite 47 mm lasts up to 24 days and costs the least since they are on the market - Xiaomi Planet
Global Version Amazfit Gtr 47mm Smart Watch 5atm Waterproof Smartwatch 24 Days Battery Music Control Leather Silicon Strap - Smart Watches - AliExpress
Amazfit GTR review: A sub $200 smartwatch that packs a punch - Wareable