Os1St Ac4 Active Comfort No Show Socks
Os1St Ac4 Active Comfort No Show Socks - is backordered and will ship as soon as it is back in stock.
- Free shipping on orders $99*
- Easy 30-day returns
- Price-match guarantee
*Free standard shipping on orders with $99 or more in full-price items (lower 48 states). Sale and oversized items do not count toward the $99.
Getting the right size is the first step to comfort. Use this guide to choose your size and width online with confidence.
How to measure your feet at home
- Measure at the end of the day, when your feet are largest, wearing the socks you plan to wear.
- Stand on a sheet of paper with your heel against a wall and mark the tip of your longest toe.
- Measure from the wall to the mark in inches or centimeters. Measure both feet and use the larger one.
- Compare with the brand's size chart on the product page.
How a good fit should feel
- Length: about a thumb's width between your longest toe and the end of the shoe.
- Width: your foot shouldn't spill over the footbed or feel pinched at the ball of the foot.
- Heel: snug, with little or no slipping as you walk.
- Arch: the arch support should meet your arch without pressing into it.
Width guide
| Width | Women | Men |
|---|---|---|
| Narrow | 2A (AA) | B |
| Standard | B (M) | D (M) |
| Wide | D (W) | 2E (W) |
| Extra wide | 2E (XW) | 4E (XW) |
Shop wide width shoes.
Brand sizing notes
- European sizes (Birkenstock, Naot, Alegria, Dansko, ECCO): sized in whole European sizes. If you are between sizes, most customers size down and choose a regular width.
- Dansko clogs: should feel snug at the instep with a little heel movement as you walk; that is by design.
- OOFOS: most styles use unisex (men's) sizing. Women usually order two sizes down from their usual women's size.
- Running shoes: many runners go up a half size for long distances because feet swell.
Brand size charts are on each product page. Still unsure? Contact us and we'll help you choose, and remember returns are easy within 30 days on unworn shoes.
Os1St Ac4 Active Comfort No Show Socks
The AC4 wraps the whole foot in even, all-day compression with extra padding under the sole — OS1st built it as a general comfort sock, and it shows: less foot fatigue on long days, fewer blisters. No-show cut stays put in low-profile shoes. It's comfort, not a brace — if you need targeted arch or heel support, look at the FS4 instead.
Description
Description
The OS1st AC4 Active Comfort Sock delivers lasting comfort with contoured padding and cushion, a seamless design, a thin breathable construction, and blister protection. Great for runners or anyone with an active lifestyle, the light compression supports the foot while helping circulation. The anatomical left/right design gives you the perfect fit.
Our fit team's notes: the thin construction keeps air flowing for a cooling sensation. For best fit, refer to the sizing chart. Wash gentle on cold, tumble dry on low heat. No bleach or fabric softener.