Customized version of http://www.thingiverse.com/thing:290804

Created with Customizer! http://www.thingiverse.com/apps/customizer/run?thing_id=290804

Using the following options:

outer_cutout_radius = 1.5
ruffle_width = 12
height = 23
outer_cutout_inset = 1.25
surface_type = 1
outer_cutout_shape = 32
inner_cutout_shape = 3
inner_diameter = 53
passage_width = 1.25
cutout_tilt = 12
cutout_count = 12
inner_cutout_radius = 2.25