Customized version of https://www.thingiverse.com/thing:4149228

Created with Customizer! https://www.thingiverse.com/apps/customizer/run?thing_id=4149228

Using the following options:

hole_diameter = 58
extend_distance = 5
inner_diameter = 30.0
outer_ring_width = 2.8
cover_thickness = 2.8
slit_width = 1.2
num_slit = 20
gap = 1.2
frame_thickness = 2.5
frame_height = 12
$fn = 108