A women's open toe knee-high stocking from Truform's Ladies' Opaque range, knit in a soft opaque microfiber knit, finished with soft stay-up top. It delivers 20-30 mmHg firm graduated compression. Most wearers are managing a diagnosed venous condition and wear it daily. Browse the Truform women's range.

The numbers are the pressure at the ankle, measured in millimetres of mercury, decreasing as the garment moves up the limb. At 20-30 mmHg this is Truform's firm class, and the most commonly prescribed level. Truform indicates it for tired aching legs, moderate varicosities, moderate varicosities during pregnancy, moderate edema, post-sclerotherapy and other surgery, superficial thrombophlebitis, and helping prevent recurrence of venous ulcerations. If you're unsure which level applies, our compression therapy guide explains each one, or see our varicose veins.

Compression sizing isn't standardised across brands — a Medium in one brand is often not a Medium in another, so go by your measurements rather than the size you wore last. Measure your ankle at its narrowest point and your calf at its widest, first thing in the morning before swelling builds, against bare skin with your foot flat and the tape snug but not constricting. If your swelling has changed, or you've gained or lost weight, or you're recovering from surgery, re-measure rather than reordering your previous size. Our measuring guide walks through each measurement.

Firm and extra-firm garments are the hardest to put on, and most difficulty comes from technique rather than the garment. Turn the stocking inside out to the heel, work your foot in first, then roll it up the leg in stages rather than pulling from the top. Donning aids such as a stocking donner, donning gloves or a slip sock are worth considering. Full instructions are in our guide to putting on compression stockings.

Wash after each wear in cool or lukewarm water with a gentle solution — never fabric softener or bleach — and always air dry away from direct heat, since a machine dryer permanently damages the elastic. With daily wear and proper care, expect roughly three to six months before the compression declines, so most people rotate two pairs. Full instructions and washing solutions are in our care guide.