Designed for parapet walls to provide a clean, professional edge, counter flashing delivers waterproof protection for vertical terminations. DERBIGUM offers a variety of 1-piece and 2-piece versions to meet any project needs. DERBIGUM 2 Piece Counter Flashing is available in three versions: Surface Mounted, Reglet and Thur-wall. The two-piece design is easily installed by hooking and rotating the flashing to snap into the receiver and can be taken apart for easy roof repairs.