The Garmin epix Pro (Gen 2), 51mm Glass Edition is the largest case size in Garmin's premium AMOLED multisport smartwatch range, built for buyers who want maximum battery life and screen real estate over a smaller, lighter watch. It carries the full epix Pro feature set — full-colour AMOLED mapping, multi-band GPS, wrist heart rate, Pulse Ox, HRV status, sleep coaching, Garmin Pay, on-watch music storage (up to 2,000 songs via Spotify/Amazon Music/Deezer), and a built-in adjustable LED flashlight — on the series' largest and sharpest 1.4" AMOLED display at 454 x 454px. As a Glass Edition it uses a Corning Gorilla Glass DX lens with a Slate Gray-finished stainless-steel bezel and a black silicone band, rather than the sapphire/titanium build of the Sapphire models, keeping the price down while sharing the same case size and battery. It is rated 10 ATM water resistant and weighs about 98g. Battery life is the standout reason to choose the 51mm: up to 31 days in smartwatch mode with gesture wake (about 11 days with always-on display), and up to 145 hours in max-battery GPS mode — roughly triple the smartwatch runtime of the 42mm model. Best suited to multi-day expedition or ultra-endurance use where recharging is inconvenient.