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:

shank_inner_diameter = 9
key_ring_hole_with_rounded_edges = 0
number_of_center_sides = 6
bow_thickenss = 8
depth_of_center_hole = 15
shank_outer_diameter = 12
bow_center_coeff = 1.3
bow_number_of_handles = 2
key_ring_hole = 0
key_ring_hole_diameter = 5
bow_round_corners_radius = 0.6
shank_height = 20
bow_handle_length = 20