The Siemens 3SF4102-1B is a numerical LED display for flush mounting, built with AS-Interface onboard. It shows four digits in red, each 13 mm tall — readable at arm's length on a panel or machine fascia. The AS-Interface connection means it pulls power and data over a single two-wire bus, so you're not running separate signal cables back to the controller.
Flush-mount design lets you cut a standard panel opening and drop it in with the bezel sitting flush. The AS-Interface bus handles the wiring — just daisy-chain the flat cable through the display and the gateway. It's a panel-side indicator, not a DIN-rail module, so plan for the cutout and the bus drop in your enclosure layout.