Panel fit and what the 50 ms sampling means
The PXF9APS2-MBCA1 is a self-tuning 1/4 DIN (96 x 96mm) compact temperature and process controller.

PXF9APS2-MBCA1, 1/4 DIN (96 x 96mm) self-tuning temperature and process controller, 50 ms sampling speed, compact panel-mount form factor.
The PXF9APS2-MBCA1 is a self-tuning 1/4 DIN (96 x 96mm) compact temperature and process controller.