Scotty Transducer Mounting Arm is designed for kayaks and small boat use. Made of High strength composite material that will give you years of service- without any corrosion problems. Telescopes from a compact 11.5 to 18" length. Fully adjustable design allows for any angle. Includes: Scotty 438 Gear-Head Track Adapter, Scotty 415 Slip Disk for micro adjustments, and Scotty Transducer Arms. The 141 track adapter mount will allow you to install on of Scotty's fish finder mounts or any Scotty post mount product. (Track and transducer not included).