Kinetic Development Group MREX20 AXL Tactical Rails Black. The SRX was developed with the same mindset as our MREX rail lineup. Made from strong 6061-T6 aluminum this durable receiver extension was built for comfort and ergonomics. The added 3 6 inches gives you an enhanced grip further down the Stribog while providing plenty of real estate for added accessories. The SRX was also designed around the option of adding a variety of suppressors with plenty of ventilation to ensure a comfortable cool grip even after extended suppressor use. Specifications for Kinetic Development Group MREX20 AXL Tactical Rails: Manufacturer: Kinetic Development Group Handguard Length: 3.5 in Handguard Material: 6061 T6 Aircraft Grade Aluminum Mount Type: M-LOK Package Contents: Kinetic Development Group MREX20 AXL Tactical Rails Kinetic Development Group MRX5-A-060: MREX20 AXL Tactical Rails Black