Mercury - Flush Mount Trim Pad (Dual Engine) Helm Trim Control 87-879303A02. Overview. This low-profile trim pad gives dual-engine DTS boats a clean way to adjust trim for both engines right from the helm. It sits flat in the dash, so it doesn't take up space or get in your way when you're running the boat. The buttons feel natural under your thumb, making it easy to bump each engine up or down as conditions change. It's a simple piece that helps daily driving feel smoother and more controlled..