Primary Arms SLx Micro 3x Magnifier. The SLx 3x MicroMagnifier is an exciting approach at optical magnifiers, combining high-clarity 3x magnification with a miniaturized body. This new optic is part of Primary Arms' SLx line. SLx optics built Primary Arms Optics' reputation for innovation, reliability, and value. All SLx optics undergo rigorous field-testing during development to best serve users in any environment. Weighing only 5.3 oz, the SLx 3x MicroMagnifier is a miniaturized, lightweight magnifier that extends the effective range of a red dot sight or 1x prism scope. The SLx 3x MicroMagnifier features an innovative 'micro-sized' design that reduces its footprint compared to traditional magnifiers. This makes it ideal for close-quarters carbines, where agility, ergonomics, and handling speed are paramount.