This is a highly popular automatic diver's watch from Heimdallr, modeled after the MM300, and is very popular with overseas enthusiasts. It features a sapphire crystal, ceramic bezel, and a Seiko NH35 movement. It has a substantial weight and a very high-quality feel. I own the original, and this is quite similar. Case diameter: 44mm 300m water resistance Ceramic bezel Sapphire crystal glass Lug width: 20mm Recommended for those who like Prospex Marine Master SBDX, SBDY, SBDC, etc.