ProMag PM237B AR-15 9mm Quick Change Adapter Block

The ProMag PM237B Magazine Quick Change Adapter Block enables installation in AR-15 and M16 lower receivers to accept 9mm Colt/SMG-style magazines when paired with a compatible 9mm upper receiver. Made in the USA, the adapter is molded from high-strength polymer and includes steel hardware, a roller, ejector, and bolt stop. Installation is designed to be quick and does not require removal of the bolt stop roll pin. The PM237B provides a practical conversion solution for builders and shooters using 9mm upper assemblies.

Key Specifications

• The model is PM237B.
• Caliber is 9mm.
• The material is polymer with steel hardware components.
• The finish is black.
• Compatible with AR-15 and M16 lower receivers.
• Allows use of 9mm Colt/SMG-type magazines with 9mm upper receivers.
• Includes roller, ejector, and bolt stop as part of the steel hardware set.
• Installation permits a quick fit without removing the bolt stop roll pin.
• The product type is an adaptor block designed for conversion kits.
• Manufactured by ProMag in the United States.

Designed for straightforward installation and long-term service, the PM237B is a practical component for any 9mm AR conversion project. Its polymer body with steel internals balances durability and weight savings, making it a reliable choice for builders and shooters seeking a simple, effective magazine interface solution.