This flush mount insert is designed to hold the Holley 3.5 inch screens. The flanged insert allows the screen to be recessed much like a gauge would be. Perfect for anyone that is making a dash or an instrument panel. This flush mount insert is designed to hold the Holley 3.5 inch screens. It is perfect for anyone that is making a dash or an instrument panel. The flanged insert allows the screen to be recessed much like a gauge would be. It can be drilled and screwed or just epoxied in place. Made from durable ABS plastic to survive in the heat and cold.