From Halopedia, the Halo wiki
SUTURE was part of a relatively new series of experiments approved for testing on ANVIL Station. The set is specially designed for use by Spartan combat medics, another concept undergoing testing as part of the same experiments.
The SUTURE armor set was originally created as a useable armor permutation for Halo Online, a cancelled Halo 3-derived multiplayer game developed by Saber Interactive and Innova Systems which was intended to be released exclusively in Russia for the PC. After the game's cancellation in 2016, the armor was one of twelve sets introduced to Halo 3 in The Master Chief Collection as part of the game's fifth season in 2021.
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