This is a clear protective cover for the front of the CM-170W. 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 simply veclros (provided) to the front of the monitor and is easily removable. This inexpensive clear cover is an easy way to safeguard the LCD panel and is much less expensive to replace if it gets scratched or damaged than replacing the LCD panel itself.
The CPC.CM17 is made of a very neutral optical grade acrylic that is scratch resistant and extremely lightweight.