Super telephoto lens B500 - HD premium quality - Focal length: 50 mm - Aperture: f/2.5 - Aperture angle (horizontal x vertical): 8° x 6° (up to 5MP resolution) and 9° x 6° (6MP resolution) - To mount this lens on the M2x, the extended lens protection cap is required (MOBOTIX accessory: MX-M24M-OPT-LCGL)