This Belleville Ultralight Marine Corps Combat Boot 510MEF is the newest Marine Expeditionary Footwear. Fusing a moccasin-like Strobel constructed upper to an ultralight, direct-injected PU midsole provides one of the lightest, most flexible, and most durable combat boots on the market. Weighing in at just 20.6 ounces per boot, the 510 MEF is a lightweight boot that offers toughness and durability no matter the terrain.