ProMag PM237B Adapter Block | AR-15/M16 | 9mm

The ProMag PM237B is a quick-change adapter block designed to install into AR-15 and M16 lower receivers to allow use of 9mm Colt/SMG-type magazines with compatible 9mm uppers. It is manufactured in the USA and combines a high-strength polymer body with steel hardware where needed for wear items. Installation is designed to be straightforward and does not require removal of the bolt stop roll pin.

Typical uses include range training where economical 9mm conversions reduce range costs, and competitive or practice shooting where magazine compatibility and fast reloads matter. The PM237B suits builders and shooters looking for a durable, serviceable adapter block for 9mm-capable AR-style builds.

Product Specifications

• The brand fit is AR-15 Platform.
• The caliber/gauge is 9mm.
• The finish is Black.
• The material is Polymer with steel hardware for wear components.
• The model fit is AR-15, M16.
• The model name is Magazine Quick Change Adapter Block.
• The product type is Adaptor Block.
• The color is Black.
• The full description reads AR-15/M16 9MM Magazine Quick Change Adapter Block.
• The subcategory is listed as Conversion Kits.
• The make is identified as AR-15.
• The make/model field is AR-15.
• The manufacturer part number is PM237B.
• The weight is listed as .2.
• The UPC is 708279013805.

The PM237B offers a simple, robust solution for shooters converting an AR-15/M16 lower to accept 9mm Colt/SMG magazines. Its polymer construction keeps weight low while the steel roller, ejector and bolt stop hardware address critical wear points. If you need a straightforward adapter block that installs without disassembling the bolt stop roll pin and was made in the USA, the PM237B is built for dependable use in training and practical shooting applications.