Just about every gearcase seal basically contains two individual seals. The inner seal works to help keep the oil inside the gear case, and also the outer seal keeps the water out. Trustindex verifies that the original source of the review is Google. Very good folks to work with, pleasant https://dantegsahi.wikipresses.com/5519327/how_mercury_outboard_jet_motors_for_sale_can_save_you_time_stress_and_money