Product review (1 stars): but it is next to useless! It only has three sides
Just received this item and maybe I didn't pay close enough attention when ordering, but it is next to useless!  It only has three sides....

I guess the idea is to get the water out onto the kitchen floor when one can see it, but every D/W leak I've ever had has been a very slow drip - like the one from the TWO YEAR OLD Kenmore/Whirlpool.  (The previous Hotpoint lasted 24 years....)  If the recess for the D/W has vinyl flooring, it might work OK for you, but in my kitchen, the D/W sits on H/W flooring; I installed a metal threshold so the edge of the sheet flooring wouldn't get damaged by repeated removals/installs.  I also have a 9 volt water alarm.

The only situation where this item might be of use is if the kitchen flooring is all wood.  If it's vinyl or tile, you'll know about a leak soon enough without this product, so don't waste you money.  Thank goodness Amazon has a nice return policy.