These subseries come with Carbon Core Guard DWE-5600[3229] GA-2000[5590] GA-2100[5611] GG-B100[5594] GMA-S2100[5611] GR-B200[5635] GST-B200[5608] GST-B300[5631] GST-B400[5657] GWF-A1000[5623] GWR-B1000[5588] MTG-B2000[5636] G-Shocks with CarbonCoreGuard have a carbon fiber reinforced resin case, which protects the module.This technology adds shock resistance, rigidity, and resistance while at the same time reduces weight.