Tunnels are generally ventilated by rolling up the sides and opening the doors at each end. However, additional ventilation is often needed on extremely hot and humid days and the best location for maximum ventilation is in the roof. The American designed Ken-Bar High Tunnel Vent is a useful and simple to install product consisting of a 30x14 inch vent that is inserted from the outside into an area created by carefully cutting the plastic cladding. A chimney-effect movement of hot air out of the tunnel is created. The vent is constructed of clear rigid plastic mounted on an aluminium frame (36x21"). Two types are available; a manually opened type or one that opens automatically within pre-set temperature ranges. E-mail: info@ken-bar.com www.ken-bar.com