The HALO AR Socks are Fourth Element’s warmest drysuit socks to date, combining aerospace-grade insulation technology with a low-bulk, high-performance design for extreme cold-water diving. Developed for divers who spend extended time in cold environments, the HALO A°R Socks use advanced Inner Space Technology with ARGON™ aerogel insulation. This material, originally developed for space and cryogenic applications, delivers phenomenal insulation while remaining thin, flexible and less buoyant than traditional alternatives.

The A°RGON™ aerogel is embedded in a compression-resistant matrix, allowing the socks to maintain insulation performance even under pressure. A soft fleece lining enhances comfort, while the wind- and water-repellent stretch outer layer allows the socks to be worn comfortably throughout the day.

With a three-layer construction throughout, the HALO A°R Socks offer noticeably more insulation than standard drysuit socks while keeping bulk to a minimum. Correct sizing is essential and should be based on shoe size rather than drysuit boot size. Divers using tight-fitting drysuit boots may need additional room to accommodate the sock thickness.

As a key highlight of Fourth Element’s 2026 range, the HALO A°R Socks are designed for serious cold-water divers who prioritise warmth, efficiency and long-term comfort.

A°RGON™ aerogel extreme thermal insulation
High insulation with reduced thickness and buoyancy
Three-layer construction for cold-water performance
Soft fleece inner lining
Water-repellent outer layer
Stretch fabric for a close, comfortable fit
Machine washable

The socks feature three layers throughout and, therefore, are slightly thicker than the Hotfoot Pro.

Order the socks according to your shoe size, rather than the size of the boots on your drysuit, as a snug fit is essential.

In some cases, there may not be enough room in your drysuit boot when using the HALO A°R Sock.

If you are using an Argonaut drysuit, try removing the footbed for a little more room.

If you are purchasing a drysuit, consider sizing your boots one size up, especially if you are at the upper end of a size.

Outer: 83% Polyester, 13% PU, 4% Elastane Insulation: A°RGON™
Inner: 68% Polyester 32% Recycled S.Cafe’ Polyester
Machine washable.