Noise attenuation units are disclosed that are connectable in a system as part of a fluid flow path. Such units include a housing defining an internal cavity and having a first port and a second port each connectable to a fluid flow path and in fluid communication with one another through the internal cavity, and a noise attenuating member seated in the internal cavity of the housing within the flow of the fluid communication between the first port and the second port. The noise attenuating member enables the fluid communication between the first port and the second port to flow through the noise attenuating member.

An intake structure of an outboard motor supplying intake air to an internal combustion engine for the outboard motor has an engine cover covering the internal combustion engine for the outboard motor, an inner cover disposed on an outside of the engine cover, and a top cover covering the inner cover. The inner cover and the top cover form an intake duct supplying intake air to the internal combustion engine for the outboard motor.

Noise attenuation units are disclosed that are connectable in a system as part of a fluid flow path. Such units include a housing defining an internal cavity and having a first port and a second port each connectable to a fluid flow path and in fluid communication with one another through the internal cavity, and a noise attenuating member seated in the internal cavity of the housing within the flow of the fluid communication between the first port and the second port. The noise attenuating member enables the fluid communication between the first port and the second port to flow through the noise attenuating member.

A muffler for a filter system has a base body with an inlet opening. A fluid guiding rib is externally arranged on the base body so as to guide a fluid to be filtered by the filter system toward the inlet opening of the base body. The fluid guiding rib extends along a first flow direction, wherein the fluid to be filtered passes through the base body along the first flow direction. A filter system with a filter housing and a filter element removably received in the filter housing is provided with such a muffler. The muffler is attached to the filter housing.

A vehicle shown herein is a side by side utility vehicle having frame configured to effectively transfer various loads throughout the frame as whole. The vehicle may further or alternatively include a routing tray configured to retain various fluid lines of the vehicle, a transmission including a passive duct acoustical attenuation device, a door seal configured to allow the frame to contact the seal at an angle, a modular door actuating mechanism, and/or a modular skid plate.