A classic vintage styled vintage button-down shirt. Based on the Ben Sherman mod-fit and with full back pleat, this is a 100% cotton, with front breast pocket. same vintage patterns of the 60s and 70s versions. 
Approximate sizing as follows:
S – 36″ – 38″
M – 38″ – 40″
L – 40″ – 42″
XL – 42″ – 44″
2XL – 44″ – 46
3XL – 46″ – 48″