Suitable for homeowner, building contractors, and HVAC Professional want Stable ventilation solution Produced from, this vent Caps features a standard duct Interfaces designs that is, robusts, and resistant The Hooded Wall Vent Caps with Check Valves effectively prevents backflow, ensuring the efficient operate of your ventilation Systems enhances your ventilation setups with this Multifunction vent Caps, designs to maintain airflows integrity across various architectural environment Perfectly suited for residential and commercial building ventilation systems, especially in kitchen and bathroom exhaust applications, Manufacturer: YanFengPro