SIGMA® lens for AVIGILON™ HD Pro series IP security cameras. LEFS183518SI 18-35mm varifocal lens provide 42.2° - 73.8° horizontal angle and support Auto-Iris functionality. f/1.8, Auto-Iris, Vari Focal | Recommended for 4K-5K H4PRO-B | Highest image quality available, vari-focal, excellent in long ranges.