Product DescriptionThe Geissele Automatics MK4 Super Modular Rail (SMR) is a rugged, free-float M-LOK handguard built for AR-platform rifles. Designed around a full-length M1913 Picatinny top rail, the MK4 provides ample mounting space for optics, iron sights, and clip-on devices. Integrated forward Picatinny rail sections at the 3, 6, and 9 o'clock positions and extensive M-LOK slots give you flexible options for lights, lasers, vertical grips, and other accessories. The rail incorporates generous venting for heat dissipation and uses Geissele's proprietary 2.25-inch barrel nut to increase receiver interface surface area for a straight, rigid platform and consistent zero repeatability.Product Highlights Free-float MK4 Super Modular Rail (SMR) design helps maintain accuracy and consistent point of impact Full-length M1913 Picatinny top rail for optics, back-up sights, and clip-on accessories Forward integrated Picatinny sections at 3, 6, and 9 o'clock plus M-LOK mounting interfaces for modular accessory setup Maximum venting in the lower 45Adeg quadrants for improved heat dissipation and reduced weight Geissele proprietary 2.25" barrel nut increases rail-to-receiver contact for a strong, true alignmentSpecs Brand: Geissele Automatics Product Line/Model: MK4 Super Modular Rail (SMR) Handguard Length: 10.5 in Color: Black Mount Type/Interface: M-LOK Top Rail: M1913 Picatinny Material: 7000-series aluminum Finish: Type III hard coat anodized Inner Diameter: 1.35 in Outer Diameter: 2.11 in Height: 2.4 in Weight: 10.6 oz Country of Manufacture: USA Manufacturer Part Number: 05-1656B UPC: 810081130097Disclaimer: We strive to provide accurate and up-to-date product descriptions, specifications, and images; however, errors or omissions may occasionally occur. We are not responsible for any inaccuracies or discrepancies in the content provided. If you notice anything incorrect or unclear, please contact us so we can correct it. When in doubt, we recommend verifying details directly with the product's manufacturer.