Humminbird Helix 15 Screen Protector Apex Series The round mounting plate is

The round mounting plate is typically used on fiberglass boats

Crafted to provide a flat and stable surface

With the Patented Reverse Telescopic design it is the only mount on the market that allows you to see your graphs from the deck of your boat up to 17 inches in height with just the twist of a knob

and helps conserve battery life by allowing lower screen brightness

The Flex HD is 18 1/2 inches at the lowest vertical point and it raises up to 26 inches

Humminbird Helix 15 Screen Protector Apex Series The round mounting plate istempered glass screen protector for humminbird helix 15. 9h hardness. great insurance for protecting your sounder screen