Compression is the rare merch category where the product is literally a number. Four questions get you to the right one, and any supplier who dodges them has answered you anyway.

Ask for the class, and the measuring point

A stated range in mmHg, and where on the garment it was measured.

‘Firm’ and ‘premium’ are adjectives. A class is a specification.

Check that it graduates

Firmest at the ankle, easing up the calf — that profile is the entire point.

A sock tightest at the top is not a milder version of compression.

Refuse to size by shoe size

Ankle circumference, calf circumference, and length to below the knee.

Ask whether wide-calf and long-calf exist as real blocks or as apologies.

Ask how long the pressure lasts

Every garment loses pressure with washing; an honest supplier gives you a replacement window.

A pair that still looks new at month eighteen is not still working.

Then choose the colour

Dress-code blacks and navies, travel packs, team colourways — all safely secondary to the class.