United Kingdom Size Maximum to US: Small / 51mm

United Kingdom Size Maximum: Corresponds to a nominal width of 69 $\text{mm}$ (2.72 $\text{in}$), length of 220 $\text{mm}$ (8.66 $\text{in}$), average structural girth of 138 $\text{mm}$ (5.43 $\text{in}$), and fit category Maximum Bariatric / Ultra Wide.

US: Small / 51mm: Corresponds to a nominal width of 51 $\text{mm}$ (2.01 $\text{in}$), length of 180 $\text{mm}$ (7.09 $\text{in}$), average structural girth of 102 $\text{mm}$ (4.02 $\text{in}$), and fit category Small / Regular-Narrow.