Size description:
S- recommend for pet weights 4-5.5kg / 9-12 Ib
M-recommend for pet weights 5.5-7kg / 12-15Ib
L-recommend for pet weights 7-10kg /15-22 Ib
The white British shorthair model is 4.5kg/10 Ib and is wearing a size S.
It is recommended to measure your pet before ordering.