Prevents inside corner cracking when installed against a ceiling or concrete deck that may be subject to movement. A co-extruded flexible gasket compresses and expands during deflection. Provides protection for up to 7/16" of deflection. Tear off strip leaves a clean finished edge. Can be used in fire-rated and non fire-rated assemblies. UL Classified when installed with the proper associated fire rated assembly.
https://www.trim-tex.com/products/overview/commercial-beads/deflection-beads/wall-mounted-deflection-bead