The knobs is large and provide rubber fittings that will add in adjustment. High Quality Material This marine mirror shell is made of high-impact plastic material and shochproof glass, strong and sturdy. Our mountable boat mirror is designed with 2 thumbscrews. Mounted on marine, ski boat, for speedboat, pontoon boat, water sport, watercraft surfing and so on. all knobs are really large and easy to turn tight, you can easily adjust the screws and fit multiple types of boat windshields. Just hand screw the head in and your windshield frame is ready to go. universal boat mirror with 1 rubber pads, with the protection pads can protect your boat windshield frame from scratching. The joint ball at the back of the pontoon boat mirror can be adjusted easily instead of using tools. Boat Rear View Mirror 7x14, Universal Marine Jamaica 11/o - Finance Boat Rear View irror 7x14, Universal arine... There is two type of gauges which are mechanical and electrical. Mechanical is what the 72 Corvette used and electrical is what most modern cars use Car Rear View Mirror Boat Rear View Mirror 7"x14", Universal Marine s, Wide-angle Convex Boat Mirror For Ski Boats Pontoon Boat Water Sport Wakeboarding Surfing With 1/2"-1" Windshield Frames Rearview Mirror Wide Application Universal marine mirror 7x14 incn, fit with marine boat rear view. Adjustable The knobs of the boat mirror rear view can be adjusted to fit your need, Attached it to the windshield of your boat, you will have a good view behind your boat without having to turn around 【Universal Marine Mirror】This marine rear view mirror is suitable for ski boats pontoon boats and other boats with windshield frames, the bracket of the pontoon boat rear view mirror fits windshield frames with a thickness between 0.5 to 1 inches. 【High Quality Material】Boat mirror rear view side mount constructed of ABS plastic up here around the housing on the boat mirror so it’s going to hold up again mirror impacts and then it has a metal bracket down here that is attached to our windshield frame now. The knobs are really large so easy to turn tight 【Improved Version Metal Clamp】Upgrades metal clamp of marine mirror for boat is more sturdy than a plastic one, and provides better stability than suction cup that are easy to fall out.