From Halopedia, the Halo wiki
The parafoil is a triangular parachute in the shape of an airfoil, which is similar to the shape of airplane or the wings of a glider. Parafoils are most likely made from extremely strong materials, as some are capable of supporting the weight of an armored SPARTAN: approximately 1,000 pounds. The deployment package for a parafoil is known as an airfoil carapace.
SPARTANs descending from low orbit may use parafoils in lieu of SOEIVs. For example, Maria-062 used a parafoil while testing John-117's Mark VI MJOLNIR armor. They are also used by UNSC Army Airborne.
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