Application video showing how Hannoband 3E can be used to seal windows to RAL and EnEV standards of weather tightness. The easiest way to seal windows reliably and efficiently. Hannoband 3E: This is a three-in-one product for sealing window frames in buildings. No need for a foam infill. No need for an internal membrane. Just one product required. Virtually foolproof sealing to the highest specifications. Technibond Window Tapes, Sealing tapes.