Abstract: A system comprising a handle having a gripping end and a working end. The system also comprising a filter engagement tool. The filter engagement tool is coupled to the handle. The filter engagement tool has a filter engagement means.

Abstract: A system and method for synchronizing an oscillator with multiple phases at a desired phase angle difference. A relative measure of a phase angle difference between two phases permits each phase to be controlled to obtain the desired phase angle difference. The various phases may have different inherent frequencies that are synchronized to a common frequency such as an average of the different frequencies.

Abstract: A method and apparatus is provided for exhausting air from the interior of the occupant compartment of a movable vehicle to protect occupants from undesirable or contaminated air originating within or outside the vehicle. The method incorporates an exhaust system to remove air from the rear of the vehicle while maintaining air flow through the vehicle, preventing air back streaming, and sustaining a relative negative air pressure inside the occupant compartment. The invention prevents the breathing of air contaminated by people or animals being transported in vehicles and can protect occupants from diseases, odors, bio-hazards, and other undesirable or contaminated air in an enclosed compartment.