The UB11 Vepac vent is an in-line unit with a multi-purpose base which will provide inconspicuous ventilation in natural and manmade slate roofs (suitable for 600mm x 300mm and 500mm x 250mm). Ubbink now also offer a larger unit which is only suitable for 600mm x 300mm slates. UB11s are suitable for high or low level ventilation in roofs of 25 degrees and over. Each vent has a slotted inhibitor to keep out large insects and vermin and provides a free vent area of 10,750mm2.This vent can be adapted for use as a service terminal with a vepac connector and lower pipe (100140294605). Features & Benefits Matching design to UB39 for a uniform finished look Built in grille to keep out large insects and vermin. Suitable for roofs with a pitch of 25 degrees and over Product Specification Material: UV stabilised high impact polystyrene Colour: Anthracite Free vent area: 10,750mm2