Sizes available, based on PTP measurements:
Size S:  PTP 15 inches, best fits waist 24-26 inches
Size M: PTP 16 inches, best fits waist 26 - 28 inches
Size L:  PTP 17 inches, best fits waist 28-30 inches
Size XL:  PTP 18 inches, best fits waist 30-32 inches
Length of top: ~18 inches
 
Stock running low, so get yours quickly! :)
 
Measurements may vary up to 1 inch due to manufacturing process.