The Fuji PXF4ACS2-MBKA1 is a self-tuning 1/16 DIN (48 x 48 mm) compact temperature and process controller with a 50 ms sampling speed. It's a current-production part, so no scavenging required for BOM lines.
The 1/16 DIN form factor (48 x 48 mm panel cutout) is the standard compact size for temperature controllers — fits the same panel hole as every other 1/16 DIN unit, so swapping an older controller into this slot is a direct mechanical drop-in. The 50 ms sampling speed is the key differentiator here: most general-purpose controllers sample at 100–250 ms. At 50 ms, this controller responds to process changes twice as fast as a typical 100 ms unit, which matters for closed-loop control on electrically fast heaters or thin-film processes where lag causes ripple.
That means you can spec it into a new design or replenish a spare without worrying about an imminent EOL notice.