MilTec Belgian Jigsaw Camo Pattern T-Shirt Short Sleeve 100% Cotton
New Old Stock made by Mil-Tec by Sturm 
Please see all 7 Pics. 
These Run a Bit Small. 
Measurements:
Medium:
Pit to Pit = 18"
Shoulder to Shoulder = 18 1/4"
Back of top collar to bottom of shirt = 26"
Large:
Pit to Pit = 20"
Shoulder to Shoulder = 19 1/2"
Back of top collar to bottom of shirt = 26"
XLarge: 
Pit to Pit = 21 1/2"
Shoulder to Shoulder = 21 1/2"
Back of top collar to bottom of shirt = 27"
2XLarge:
Pit to Pit = 22 1/4"
Shoulder to Shoulder = 21 3/4"
Back of top collar to bottom of shirt = 29"