The Primary Weapons Systems UXR Magwell Assembly is a precision-engineered conversion kit designed for medium frame AR-15 platforms compatible with both .223 Wylde and .300 AAC Blackout calibers.Primary Weapons Systems UXR Magwell AssemblyCompatible with .223 Wylde and .300 AAC Blackout calibersDesigned for medium frame AR-15 riflesDurable black finish constructionProfessional magwell conversion kitThis high-quality magwell assembly provides reliable magazine compatibility and enhanced functionality for tactical and sporting rifle applications manufactured to Primary Weapons Systems' exacting standards.