3M™ Privacy Filter for 21.3in Monitor, 4:3, PF213C3BProtect sensitive information in public or shared spaces without sacrificing display quality. The 3M PF213C3B Privacy Filter is specifically engineered for 21. 3 inch desktop LCD monitors with a 4: 3 aspect ratio, delivering dependable privacy while preserving the integrity of your work. This unframed filter slides neatly onto your screen, providing a clean edge to edge fit that looks close to a built in part of your monitor. The PF213C3B uses 3Ms