Customized version of http://www.thingiverse.com/thing:66900

Created with Customizer! http://www.thingiverse.com/apps/customizer/run?thing_id=66900

Using the following options:

thickness = 5
hook_width = 40
clamp_offset = 0
catch = 5
height = 20
add_catch = true
width = 40
length = 90
rounding_radius = 5
hook_offset = 0
clamp_width = 34.3