Product review (5 stars): Whirlpool 711696 seal in kit.
If you're shopping for this kit with the need for only the 1" inch diameter black rubber U-shaped seal, it's part number is 'Whirlpool 711696". This seal is inside the portable washer hose assembly faucet attachment. This seal is usually what causes leaks when old. Part number 711696 is less in cost but harder to find. Under $6.