The STU-520A is a signature pad (or signature capture device) from Wacom, typically used in industries where digital signatures are required, such as banking, retail, or legal environments. The device allows users to sign documents electronically, capturing handwritten signatures on a digital screen. The STU-520A specifically is a model in Wacom's line of signature pads.

The STU-520A Windows driver is necessary for enabling the device to communicate with a Windows operating system, allowing the captured signatures to be properly transmitted and displayed on the computer. This driver supports the Wintab interface, which allows software applications to interface with Wacom signature pads.