The X-core is designed to be worn under any drysuit undergarment as an extra layer of insulation. It is most effective when worn over a lightweight base layer such as J2 but the X-Core can also be worn as a next to skin garment.

Being sleeveless, the vest design maximizes core insulation while not restricting arm movement or adding unnecessary buoyancy. Four-way stretch fabric combined with long body design ensures a snug fit to keep you warm. The additional chest panel protects the wearer from rushes of cold air at the drysuit's inlet valve. The X-Core's fast wicking fabric moves perspiration towards the outer surface, keeping the wearer drier and warmer.