Customized version of http://www.thingiverse.com/thing:56910

Created with Customizer! http://www.thingiverse.com/apps/customizer/run?thing_id=56910

Using the following options:

_numberOfSides = 9
_part = lid
_partGap = 0.1
_resolution = 120
_insideDiameter = 27
_minimumWallThickness = 1.0
_lipHeight = 3.0
_bayonetDepth = 0.4
_interiorHeight = 5
_topBottomThickness = 1.0
_style = round