Here are some key features and specifications of the NT21-ST121-E:

Display: 5.7-inch monochrome LCD

Resolution: 320 x 240 pixels

Communication Port: RS-232C

Touch Input: Resistive touch panel

Function Keys: 20 programmable function keys

Memory: Built-in memory for storing screens and data

Programming Software: CX-Designer (Omron's graphical programming tool)

The NT21 series touchscreen panels are known for their reliability, ease of use, and durability in industrial environments. They provide operators with intuitive graphical interfaces for interacting with PLCs (Programmable Logic Controllers) and other automation devices. The NT21-ST121-E specifically offers a compact size and can be easily integrated into control panels or mounted on machines.