From Halopedia, the Halo wiki
Achoem Weapons is a major weapons manufacturer formerly employed by the Covenant, based on the continent Tolvuus on Sanghelios. They produced materiel for the Covenant military, including the Type-44 iteration of the Phantom troop carrier and the Lich deployment platform. They also took over the production of Shade turrets after High Charity's Assembly Forges were lost when the holy city fell to the Flood and was later destroyed. Achoem workshops are known to implement manufacturing sigils on their products.
During the Blooding Years, several Sangheili within Achoem Weapons' employ were allegedly loyal to those fighting against Arbiter Thel 'Vadam. Rebel Otar 'Bemet contacted these individuals and attempted to schedule a meeting to gain access to the armories of Achoem Weapons and use its weapons against the Arbiter. However, 'Bemet's plan was discovered and all involved were either killed or interrogated by the Arbiter's Swords of Sanghelios.
List of appearances