All field vent hoods are made of heavy gauge aluminum and can be used with natural gas, LP gas or oil-fired equipment. There are five diameters ranging from 3 to 8 Inch. The concentric pipe, angled outlet deflectors, and spaced plate design allow for better heat dissipation. This type of construction minimizes the effects of heat on the outside wall. The angled hood design reduces the effects of wind on the venting system. The inner and outer pipe are a continuous structure. This allows for easy installation to power venter or vent pipe and also eliminates possible positive pressure leaks in the wall section.