The Lasdrop Elite is a compact, lip seal designed for quick and easy installation. The lip seal, made specifically for marine use, is in constant low friction contact with the propeller shaft, preventing water from passing in your vessel. As in all Lasdrop models, the Elites incorporates a water lubricated alignment bearing in the housing to keep the unit properly aligned with the shaft. There is a compartment that is secured to the housing that encompasses a back-up seal, making it changeable in the future without the need of removing the shaft or entire unit. 2nd back-up seal in compartment is available as an option.