[. . . ] 1 Bronze Thru-Hull Transducer 530513-2_A Thank You Thank you for choosing Humminbird®, America's #1 name in fishfinders. Humminbird® has built its reputation by manufacturing top-quality, thoroughly reliable marine equipment. Genuine Humminbird® accessories offer the opportunity to upgrade and expand the capabilities of your Humminbird® product. About Thru-Hull Installation Following are instructions for the installation of the Bronze Thru-Hull Transducer. [. . . ] Use the pilot hole (from the outside of the hull) to drill a hole sized to fit the threaded stem of the transducer. If you are using a fairing block, drill the hole perpendicular to the water line. If you are mounting the transducer body directly to the hull, drill the hole perpendicular to the hull. Thoroughly clean and deburr the drilled hole and clean the outside of the hull. If you are using a fairing block, the block should be cut to match the angle of the deadrise of the hull. The first piece mounts outside the hull and is shaped to match the profile of the transducer. The second piece mounts inside the hull 2 Bronze Thru-Hull Transducer and provides a level surface for the fasteners. A fairing block (usually made of wood) can also serve to create a hydrodynamic water flow around the transducer body. The design and fabrication of this block varies greatly with different hull shapes; therefore, it should be customized by a qualified marine technician. If the transducer is round, a notch on the housing and stem indicates the forward side of the transducer. This type of transducer is directional in nature and must be aligned with with the front of the boat (the direction of travel). Failure to align the transducer notches with the front of the boat will result in incorrect bottom readings. Then apply a generous amount of marine sealant or slow curing epoxy inside the drilled hole and along the mating surfaces of the transducer housing. If you are using a fairing block, seal the mating edges of the block as well. Insert the transducer into the drilled hole from outside the boat, then install the nut onto the threaded stem from inside the boat. If you are using a fairing block outside the hull, you must use a similar block inside the hull to provide a level bearing surface. [. . . ] Refer to your Humminbird® product Operations Manual for the specific details of this warranty. If you have any questions, call our Humminbird® Customer Resource Center at 1-800-633-1468. and Canada, hours are MondayFriday 8:05 am to 4:30 pm Central Standard Time. [. . . ]