Casio's Master of Horizon Gold series launched in Japan in August 2026, dressing three Master of G models in Carbon Core Guard cases with stainless steel bezels finished in yellow-gold ion-plating: the Mudmaster GG-B100XMH-5A (¥60,500), Mudman GW-9500MH-5 (¥63,800), and GravityMaster GR-B300H-5A (¥49,500).
This GR-B300EC-1AJF comes from the same GravityMaster case family, in an earlier black-and-emergency-color finish built around a next-generation-aircraft-inspired design, currently in stock at CDJapan.
