Customized version of http://www.thingiverse.com/thing:9860

Created with Customizer! http://www.thingiverse.com/apps/customizer/run?thing_id=9860

Using the following options:

mount_base = 3
buckle_width = 40
buckle_gap = 10
lens_diameter = 77
circle_sides = 70
mount_width = 4
buckle_thickness = 6
mount_lip_width = 0.2
mount_height = 5
mount_lip_height = 0.1