The big plate at the base  is  designed to mount on the deck of a boat. We have a smaller base to mount on our bridge so please make sure before you order which style fits your boat the best.

We suggest you use our underplate for a more secure and stable installment. 

The locking handle allows for up to 10 inches of height adjustment along the slotted tube.

The top knuckle has secure detent adjustments to tilt your units for the best angle.

The Telescopeing Double Deck Mounts are CNC machined for precise fit and adjustments.

The picture in the listing of the Under Plate is sold seperate on the products page.