Plastic and resin models, especially newer releases, have a lot of detail already incorporated.  Yet there can be some limitations to the given medium or
perhaps reference photos or drawings may reveal that a particular detail may have been omitted or may not be accurate in terms of location or style.  
Whatever the reason, kits can be improved with aftermarket parts for various equipment and fittings. A usually neglected fitting are hatches.  
set F350002, Hatch Covers, provides 122 quality, relief-etched hatches in four different shapes (square, rectangular, oval and round).  The
round hatches are provided in three different sizes.  This would be a good set to have in your detailing toolkit.
Felix Bustelo