Halo AR Women
✓ highly advanced thermal technology | ✓ HALO A°R's achieves extreme thermal protection | ✓ thinner, less buoyant
The Fourth Element Women's Halo A°R (Halo AR) is a drysuit undersuit insulated with A°RGON™, a form of aerogel developed for spacecraft and cryogenics. It provides extreme thermal protection compared to a thinner, less buoyant garment. Body-mapped insulation, an offset chest zip with baffles, thumb loops, foot stirrups, and a P-valve-ready pocket make it a cold-water undersuit you can wear in total comfort, all day.
What is the Fourth Element Women's Halo A°R?
The Fourth Element Women's Halo A°R is a one-piece drysuit undersuit built around A°RGON™ aerogel insulation. Fourth Element describes A°RGON™ as one of the most insulating materials ever developed. The result is a thinner, less buoyant undersuit that still delivers extreme thermal protection for drysuit diving.
Incorporating highly advanced thermal technology, the Halo A°R's performance exceeds expectations of any diving undersuit. It combines the A°RGON™ insulation layer with a wind and water-repellent stretch outer layer, so it works as your main insulating layer under a drysuit.
Fourth Element Size Charts – Full (Excl. Argonaut)
All measurements in CM. Expand sections below. Swipe tables sideways on mobile. Ranges stay on one line.

About A°RGON™
A°RGON™ is an advanced form of Aerogel originally developed for spacecraft and cryogenic insulation due to its exceptional thermal properties. This high-performance material allows the HALO A°R undersuit and thermal diving gloves to provide superior insulation while remaining thinner and less buoyant than traditional options.
Halo AR Socks
With phenomenal insulation properties, this material enables the HALO A°R socks to achieve extreme thermal protection from a thinner, less buoyant combination of fabrics. With a wind and water-repellent stretch outer layer, these socks can be worn in total comfort, all day.
Zipper for ease donning
Low Bulk
Extreme thermal insulation





