This is an anti-reflective, fingerprint resistant clear protective screen cover for the BM090. The cover's primary function is to prevent damage to the LCD panel, especially from fingers that may poke and prod at the screen. The cover fastens into place securely on the chassis with 4 provided screws.
Please note that the anti-reflective treatment does not mean the cover is less reflective than the panel by itself, rather it is much less reflective than a plain acrylic cover without anti-reflective coating.