@shadyJ , Either JTR has a typo on their spec sheet or I don't know what I thought I knew
!!!
So, don't you just add Xmax each way to get the peak to peak value?
If so, the peak to peak value is 71mm which is a little shy of 3"!
4" would require ~101.6mm (rounding to 25.4mm = 1" for conversion calc)
Don't get me wrong, 3" is impressive, but it's not 4"!