You need our number twice to ventilate 19that you have to connect with a piece of hose and place it to the upper tanks. If your tank has a fine thread or a larger diameter at the outlet, You need original ventilation lid to ventilate or 2 x No. 19,, Please pay attention to: the screw cap with coarse thread, Plastic, blue, with 3/4 "ig, (Doesn't fit on IBC's with a fine thread or crossing on the front edge thread at the factory tap) If you want to buy several items, only place them in the shopping cart, Delivery time approx. 1-2 days after receipt of payment with parcel shipping so that nothing stands in the way of a positive rating from you and us. You can reach us: Mo.- Fri. from 9 a.m. to 12 p.m. and 1 p.m. to 4 p.m You can find contact information below in the legal information abou.