The Counter Flashing is compatible with the Solatube 330DS/750DS self-flashings (8" and 11" heights). It is designed to be used on roofs with a single ply membrane (PVC, TPO) or rubberized roof (EPDM). When a membrane boot is placed over the self-flashing, the Counter Flashing covers the exposed edge of the membrane boot at the top of the flashing, creating a water protection barrier. (Note: Solatube does not supply the membrane boot itself.)