The G1583 (GBM‑2100A‑1A3DR) includes Tough Solar, Bluetooth® Smartphone Link, automatic time sync, easy settings via app, world time for about 300 cities, reminders, and phone finder—all packed into its slim 2100 series profile https://saicreationswatches.com/products/g1583-casio-g-shock-gbm-2100a-1a3dr-analog-digital-watch-men