This is the sophisticated Casio G Shock G Steel Black and Silver Watch GST B400AD 1A4DR. Introducing new color variations to the lineup of slim G STEEL GST B400 models with new, improved designs made possible by a thin module and carbon core guard structure. The GST B400AD comes with a black ion plated IP bezel combined with a vapor deposition dial in G SHOCK red. The GST B400 is made possible by even further miniaturization of its parts and thinning of its modules without sacrificing any Bluetooth or solar function. Power consumption has also been significantly reduced.