The SO R55 Adaptor is a weapon attachment featured in Call of Duty: Modern Warfare 3 (2022) and Call of Duty: Warzone 2.
It is one of the Stock attachments available in MW3.
The SO R55 Adaptor is a Weapons Platform Specific Attachment, which means it is only usable within its specific Weapons Platform.
Here's how to unlock the SO R55 Adaptor attachments in COD Modern Warfare 3 and COD Warzone 2: Get the SO-14 to Level 8.
Here you can find the list of Weapon Blueprints that include the SO R55 Adaptor attachment in COD Modern Warfare 3 and COD Warzone 2: