Size Chart
Weight
Neck
Chest
XS
1-4 lbs
6-8"
8.5-11.5"
S
5-8 lbs
8-10"
11-15"
M
8-12 lbs
10-12"
14-17"
L
12-16 lbs
13-15"
18-21"
XL
16-21 lbs
15-17"
19-22"