They tout that this works for Sax, and yes, it technically does. The weakness comes in when you can "add 4 flats" so that you can "transpose" the displayed note. This is aimed at people who put capos on guitars up to the 4th fret, and it treats the displayed note as if the capo stop is the open string on a guitar... meaning, if you capo on the 2nd fret, you add 2 "flats" to the display, and it will show the new note still as "E"... This fails for any other instrument's concert tuning... so, on a sax, I don't need to "add flats", I would need to add "2 Sharps". If they were to add the ability to put in 6 sharps as well as 6 flats, then the device would play the INSTRUMENT'S note, not the concert note. Also, it displays the "sharp value" of a note, and not they typical "flat value" of a note (A#, instead of Bb)... if these components were switchable, it would be a great value to new musicians learning an instrument. I understand the limitations of the display.
I suggested this to the manufacture, and got what appeared to be a canned response without comment on my suggestions. Their prerogative, but these simple changes would make this good product amazing. Just because it can clamp onto a Sax bell, that doesn't really make it as useful as they present it to be.