Adjustable Height: This boat seat pedestal allows height adjustment between 12.76-18.7 inches (324-475 mm). Adjust the control lever to customize the ideal seat height for better visibility and superior comfort. Aluminum Alloy Construction: Our adjustable boat seat pedestal is made from heavy-duty aluminum alloy, providing increased support and durability. The thickened aluminum resists deformation and the waterproof features avoid corrosion, making it great for outdoor and marine environments. Universal Installation:Pre-drilled holes on the adjustable boat seat base make it easy to attach to your deck. Just align the holes with the components and secure the base in place. Note: Stainless steel screws are required for installation (not included). Two Ways to Use: Our adjustable boat seat mount can be used alone or with the AD75304 slider base (not included) for forward/backward seat movement. Pairing them allows more flexible seat adjustments for ultimate comfort