The Casio G-Shock GM-2100CB-1A, a rugged, shock-resistant watch with a metal-clad design, is now 24% off on Amazon, reaching its all-time low price. The digital-analog watch features a 1/100-second stopwatch, 5 daily alarms, a 3-year battery life, a day subdial, and 200 m (20 bar) water resistance.