S ∙ L 1/2 ∙ inside band circumference is 52mm

M ∙ N 1/2 ∙ inside band circumference is 54mm

L ∙ P 1/2 ∙ inside band circumference is 56.5mm

“Tyger Tyger, burning bright,

In the forests of the night;

What immortal hand or eye,

Could frame thy fearful symmetry?” 

William Blake