Product review (2 stars): SKIP THIS and order the new metal version instead!
If your anything like us you've already been through several of these as they break about once a year.  I was just about to buy my second set of these and double checked Whirlpools site for the part number and discovered....hallelujah....they finally issued a redesigned replacement for this made of metal!! The new redesigned part  # is W10712394 .  I would order the new one instead of this after you double check that its compatible with your model.

Also kudos to Whirlpool customer service, my dishwasher is a couple months past the warranty and when I contacted customer service to inquire they sent me the redesigned part for no charge.