Customized version of http://www.thingiverse.com/thing:1253263

Created with Customizer! http://www.thingiverse.com/apps/customizer/run?thing_id=1253263

Using the following options:

bow_thickenss = 8
key_ring_hole_with_rounded_edges = 0
bow_round_corners_radius = 0.6
bow_number_of_handles = 2
shank_outer_diameter = 12
bow_handle_length = 20
bow_center_coeff = 1.3
key_ring_hole_diameter = 5
number_of_center_sides = 6
shank_inner_diameter = 8
key_ring_hole = 1
depth_of_center_hole = 8
shank_height = 20