The crescent removed from the lower radius of the objective forms the Light Optimization Profile™, which gives you the low-light advantages of a large objective lens, while hugging the rifle for a lower mount and more comfortable, secure cheekweld. The 50mm VX-L® mounts as low as a 36mm riflescope, yet delivers 48.6 percent more Total Light Throughput™ (TLT). Likewise, the 56mm VX-L and VX-7L™ mounts like a 40mm, and delivers 96 percent more TLT. You’ll also appreciate the uninterrupted, circular field of view, the improved balance, and the quick, accurate aiming that comes with a low-mount cheekweld. While the objective of the VX-L and VX-7L has a crescent, your sight picture remains perfectly circular, with crisp, edge-to-edge sharpness across the entire visual field.