The D2 Delta has a titanium bezel which, simply put, is too soft to avoid scratches in normal watch use. I just got tired of painting the bezel every time I spent hours banging on something (like a lid, dashboard, etc.). This bezel ring fits snugly over the D2 Delta bezel for secure protection. In fact, it does a good job of hiding the crumpled OEM Ti bezel. In short, it's as simple as exposing the adhesive, aligning the reliefs on the bottom with the D2 screws, and pressing down. Two spare adhesive rings are supplied in excellent packaging. The key point is that this bezel fits D2 Delta Garmin watches.