I have used two other versions of Peterson Tuners, had a portable Peterson tuner for the last 20 years...it's always been the best device for accurately tuning a stringed instrument...and that includes autoharps. It was and is used on the bench when setting up guitars, bass, 6, and 12 strings for intonation. Very easy to use and very accurate. My first Peterson was a true "spinning wheel" piano tuner, but it was specifically designed for pianos and harps.
I used another company's pedal board mounted tuner while playing for groups and school kids' programs. But, after seeing the Peterson name and the half arc tuning wheel advertised by Sweetwater, your product is now mounted on my pedal board. It works great. My board is homemade. All the board members are attached via either double-sided tape or long thin tie-wraps. It's a two dimensional board, sits flat inside an old gig-bag originally made for a beginner's keyboard. All cabling and power is distributed through black plastic cable jacket. Looks decent and no noise.
Only thing that might make this tuner better might be the ability to flip the three position switch that's inside the battery pocket externally. But it's not really a big deal.
Since mine is mounted in the second row or stuntboxes, I have to be careful when activating/deactivating the mute button. I machined an aluminum extension sleeve that slips over the existing button and raises the button's height about an inch. That makes it easy to clear the modules and knobs in the row below. The Peterson is not modified in any way. It simply has an shiny aluminum extension slipped onto the mute button.
This issue will probably not affect anyone else who simply mounts the Peterson in the lower row,