Small: 7.5 inches from first hole to silver knob and 7 inches from second hole to silver knob. 

Medium: 8 inches from first hole to silver knob and 7.5 inches from second hole to silver knob. 

Large: 9 inches from first hole to silver knob and 8.5 inches from second hole to silver knob. 

X-Large: 9.5 inches from first hole to silver knob and 9 inches from second hole to silver knob.

Since we use a natural leather we suggest you do not get your bracelet wet. You will start to see a natural patina from everyday wear and the oils in your skin. The holes are a little snug in the beginning as they will begin to slightly stretch with wear.