Presma Adjustable Low Profile Gas Block, 0.875” Black Steel

The Adjustable Low Profile Gas Block, 0.875” (GBA875) is built for AR-15 platforms using .223/5.56 bull barrels with a 0.875″ diameter gas journal. Its adjustable gas system allows shooters to fine-tune gas flow for improved reliability, reduced recoil, and optimized performance—especially useful on heavy-barrel or suppressed configurations.

Manufactured from durable steel and finished in black, this gas block is designed for long-term reliability in demanding builds. The low-profile design provides clearance under most free-float handguards while still offering the strength required for larger-diameter barrels.

This gas block installs securely using set screws and includes all necessary hardware for a straightforward installation.

Features

• Adjustable gas system for precise tuning

• Fits 0.875″ diameter bull barrels

• Compatible with .223/5.56 AR-15 platforms

• Low-profile design for free-float handguards

• Steel construction with black finish

Includes

• Adjustable gas block

• Roll pin

• Mounting screws

• Hex wrench

Dimensions

• Height: 1.625″

• Width: 1.045″

• Length: 0.99″

This adjustable .875 gas block is an excellent choice for builders running heavy or bull barrels who want fine control over their AR-15 gas system without sacrificing handguard compatibility.