Thank you for your question on the Delta Soap / Lotion Dispenser. I will be happy to assist you today.
The black gasket should be installed below the deck between the deck and the mounting nut.
If you ever have any questions, concerns, or require anything further please feel free to give us a call on our warranty line at 800-345-3358 and we will be happy to assist you in any way that we can.
Delta Faucet Company
Date published: 2018-08-17