Key travel information
According to the Key Travel Chart from MusicTrader.com (attached below), key travel for Bb and A soprano clarinets is
2.5mm for upper pads (This is the distance between the outside lip of the pad and the tone hole when the key is fully open.)
3mm for the B/F# and Bb chromatic key operated by the right hand. In other words, the 11mm diameter pads.
3.5mm for the big pads.