G-SHOCK" is a shock-resistant watch that has established a new concept of toughness in watches. This model is based on the G-STEEL series, which combines metal and resin materials, and comes in popular black and gold colors. Shock-resistant construction】Core technology of G-SHOCK in pursuit of toughness, protecting the module with a shock-resistant construction. 20 atmospheric pressure waterproofing】Available for use in a wide variety of locations and situations, from everyday water work to water activities such as swimming, surfing, and jet skiing. Mobile Link function] Functions can be linked via BluetoothⓇ communication with compatible cell phones. Other Product Specifications】Tough solar power / needle evacuation function / world time / stopwatch / timer / time alarm / battery indicator display / power saving function / fully automatic calendar / 12/24-hour display system switching / operation sound ON/OFF switching function / date/day display / double LED Double LED light Details: From the G-SHOCK line of toughness watches that has continued to evolve in pursuit of insatiable strength since its launch in 1983, this model is based on the G-STEEL series, which combines different materials of metal and resin, in popular black and gold colors. The black base with gold-colored dial is a gorgeous fashion item with a design that can be used in a wide range of applications. The base model is the GST-B400 with a thin module and carbon core guard structure. The G-STEEL series, which combines toughness and design, comes in popular colors such as black and gold, making it a cool design that can be used for a wide range of purposes. The G-STEEL series is designed with popular colorings such as black and gold to provide a cool design that can be used for a wide range of purposes. World time: 38 cities (38 time zones, with automatic daylight saving time setting function) + UTC (Coordinated Universal Time) time display, home time city switching function - Stopwatch (1/100 second (less than 1 hour)/1 second (more than 1 hour), 24-hour counter, with lap/split) - Timer (set timer (set in 1 second, maximum set time: 60 minutes, measured in 1-second increments) - 5 time alarms and time signal - battery indicator display - power saving function (turns off display after a certain period of time in the dark to save power) - fully automatic calendar - 12/24-hour display system switching - operation sound ON/OFF switching function - date Date display (month/day display switching) - Day of the week display (six language switching: English, Spanish, French, German, Italian, and Russian) - Double LED light: LED light for the dial (with super illuminator, afterglow function, and afterglow time switching (1.5 seconds/3 seconds)), LED backlight for LCD section (with super illuminator, afterglow function, and afterglow time switching (1.5 seconds)) (with super illuminator, afterglow function, and afterglow time switching (1.5 sec/3 sec)) *When not linked to a smartphone, the watch operates with normal quartz precision (average monthly difference ±15 sec). Automatic time correction ■Easy clock setting ■World time: approx. 300 cities ■Time & place ■Reminders ■Cell phone search *In order to establish a communication connection with a smartphone, the dedicated "G-SHOCK Connected" application must be installed. Compatible with our specified iPhone and Android smartphones. Please check the website for details such as confirmed devices and OS compatibility status. Only devices equipped with Bluetooth are supported. Bluetooth is a registered trademark of Bluetooth SIG, Inc. iPhone" is a trademark or registered trademark of Apple Inc. in the United States and other countries. Android" and "Android logo" are trademarks or registered trademarks of Google LLC. *Other company names and product names are trademarks or registered trademarks of their respective owners. GST-B400GB is certified under the Japanese Radio Law. *The Mobile Link function is dependent on the specifications of the handset itself and the service of the telecommunications carrier in the country where the handset is used, and therefore differs on an individual basis. Contents] Main unit, box, instruction manual, and warranty card are included in the instruction manual.