The Flat Tear Away Applicator Attachment fits to the Tapepro Compound Applicator Tube.  It applies a ribbon of Joint Compound to reveals (widow sills, door jams) for the fast and easy application of Mud Set Tear Away Flat Bead.  
Made from tough industrial plastic 
Designed for installing Mud Set Flat Tear Away Bead, Mud Set Magic Corner, Trim-Tex Mud Set
Adjustable Inside Corner Bead, No-Coat Ultraflex and LevelLine 
Attaches to the Compound Applicator Tube and applies a single ribbon of compound to the plasterboard surface