4.5', 320 x 200 The STU-430 is a full-featured, monochrome signature pad w/ a new thin design & a low-profile, flat surface The 4.5'' screen is large enough to capture longer signatures as well as to accommodate soft buttons in addition to the signature area The transflective LCD is easily readable in varying light conditions Patented cordless, battery-free pen w/ 1024 levels of pressure sensitivity to accurately capture the unique pen pressure profile of a signature to be included in the biometric data State-of-the-art RSA/AES encryption to perform secure transactions Pen holder/USB cable lock combination provides a convenient area to place the pen, plus USB lock prevents accidental disconnection of USB cable Unique hardware ID so the exact device used for signing can be identified Integrated lock slot to secure the unit when needed Hardened glass protects the LCD & is highly scratch resistant Software sold separately