The pet toy consists of an inner elastomer ball having an inner ball wall, a squeaker mounted in the inner ball wall, an outer elastomer ball having an outer ball wall, an air hole mounted in the outer ball wall, the inner ball being within the outer ball. The outer frame is adapted to seal around an inlet opening of an air box which has a primary filter for filtering air prior to being provided to an engine. Cards entering the bin are engaged with and moved away from the card reader by action of a movable member. 5, the liquid has a pH of not lower than 8. The improved methods and apparatuses utilize complementary beamforming techniques, such as, for example, Subspace Complementary Beamforming, Complementary Superposition Beamforming andor Single Beam Complementary Beamforming techniques. Each pair of adjacent radial arms defines a docking bay.