A3 Industries Modular Fixed Length Folding Brace Tailhook Configuration Straight Extension Black 6.25. As long as you already have a Picatinny (1913) mount on the rear of your firearm with at least 3 slots these braces will mount to it. Available in 3 different lengths you can choose straight or offset aluminum extensions. All extensions have M-LOK slots machined into them allowing the user to mount QD sling sockets or the A3 Industries Modular cheek riser. The A3 Industries Steady-brace mounts to the end of the extension and is available in either 30percent fiber-reinforced polymer or machined aluminum. The customer can also choose the buffer tube adapter that allows the use of the Gearhead Works Tailhook. Specifications for A3 Industries Modular Fixed Length Folding Brace Tailhook Configuration Straight Extension: Manufacturer: A3 Industries Color: Black Features of A3 Industries Modular Fixed Length Folding Brace Tailhook Configuration Straight Extension Modular design for individual customization HD steel APEX hinge with positive latch and quick-deployment feature Folds left or right by simply flipping the hinge (except Sig applications) All aluminum extension arm available in straight or offset and in 3 different lengths Package Contents: A3 Industries Modular Fixed Length Folding Brace Tailhook Configuration Straight Extension A3 Industries MFB-6-50-STR-THA: Modular Fixed Length Folding Brace Tailhook Configuration Straight Extension Black 6.25