This Kel-Tec RFB Quad Rail and Picatinny Rail Riser Kit is an excellent upgrade package that significantly increases the rifle’s versatility by enabling it to be equipped with an array of modern tactical accessories. The RFB Quad Rail is machined from 6061-T6 Aluminum and attaches ahead of the rifle’s handguard on the barrel via a locking nut and set screw arrangement. The 3 Long Picatinny Quad Rail was designed with a properly relieved top rail section that allows the shooter to adjust the RFB’s gas system as needed. – The RFB Front Sight Riser mounts directly to the quad rail to produce an adequately tall front sight interface that is on the same plane as the RFB Receiver’s top rail. This enables the shooter to mount a fixed or flip-up front sight to the riser that will correctly align with a rear mounted iron sight. The 6061-T6 Aluminum Riser comes complete with 10-32 screw and hex key.