Product review (4 stars): Worked, no instructions.
Like others, we found this worked great.  But it would have been nice if some instructions were included, e.g. to reassure us which way the gasket goes in and that it's expected to be too long for some units.  We had to snip off about an inch to make it fit our Whirlpool DU1300XTVQ2).

There are a couple of youtube videos showing installation, though neither says anything about the gasket being too long.  One suggests soaking the gasket in hot water first (from the tap).  The barbed edge goes against the outside of the dishwasher tub and into the slot, with the "flap" facing inwards.

The package also included a metal door-latch to replace a plastic one which was apparently used in some models.