Determine your size

Chest: Measure under your arms horizontally, at most of the larger chest
Neck: Measure horizontally at the base of the neck

Size
S
M
L
XL
XXL

3XL

Chest (cm)
82-89
90-97
98-105
106-113
114-121
122-129
Neck (cm)
37-38
39-40
41-42
43-44
45-46
47-48