Note that 0 in dB scale indicates a 1:1 ratio with something, and not a zero in linear scale. Indeed, a zero in linear scale corresponds to -infinity in dB scale.
For sound, dB is shorthand for dB SPL, or dBs above 20 μPa, which is roughly the threshold of human hearing. So 0 dB means 1:1 with that threshold, or essentially “silent”.
I think most people would intuitively conclude as much without knowing the specifics, so it’s not unclear or wrong to label this device as 0 dB (unless it actually does produce an audible sound, or course).
Note that 0 in dB scale indicates a 1:1 ratio with something, and not a zero in linear scale. Indeed, a zero in linear scale corresponds to -infinity in dB scale.