The Siemens 3RK1207-3BQ13-0AA3 is an AS-i analog input module that reads PT100 linear temperature sensors and communicates over the AS-i bus to a Siemens S7 controller. It's a current-production part, so you can spec it into a new BOM without worrying about obsolescence.
What the description means for fit
The description calls it an 'AS-I ANALOG IN MOD,PT100 LINEAR,STD,S7'. That means it's an analog input module for the AS-i (Actuator-Sensor Interface) network, designed to accept a PT100 RTD signal and output a linearized value. The 'STD' likely refers to the standard AS-i profile, and 'S7' confirms compatibility with Siemens S7 PLCs. If your line uses PT100 probes for temperature monitoring and you're on an AS-i bus with an S7 controller, this module drops in without extra signal conditioning.