The Ware for March 2022 is the front-end electronics module for a Sony (now Magnescale) BL55 laser scale. The winner is Eben Olson (congrats, email me for your prize!), but Willmore guessed the full model number after the “interesting half” was also posted (I’m impressed!). It’s pretty amazing how a full laser interferometer is packed into such a tiny package; it’s the sort of thing that I wouldn’t believe was possible until I saw it with my own eyes.
Congratulation, Eben! I’m curious how you came to your conclusion.