The model (height 5’6″) is wearing a Small size.
To choose the correct size for you, measure your body as follows:

Size |
Length |
Chest |
Shoulder |
Sleeve Length |
S(38) |
27 |
39 |
17 |
24 |
M(40) |
27.5 |
40 |
17 |
24.5 |
L(42) |
28.5 |
42 |
18 |
25 |
XL(44) |
29.5 |
44 |
18.5 |
25 |
XXL(46) |
30 |
46 |
19 |
25.5 |