Lavatory drain replacement - gasket?

[calantha]

I'm installing a new drain and pop-up on my bathroom sink. The replacement I bought has a part that I'm not sure what to do with. This picture on the Aubuchon Hardware site shows the piece. It's the black gasket (?) below the flange, that sort of cups upward. It's a separate piece from the large black rubber washer that goes up against the bottom of the sink. What is this for?

 

[Terry]

That can go under the flange instead of putty.

 

[Sponsor]

 

[hj]

If your drain is anything other than polished chrome that gasket is so you do not use plumber's putty, which could tarnish the finish.

 

[calantha]

I'm installing a new drain and pop-up on my bathroom sink. The replacement I bought has a part that I'm not sure what to do with. This picture on the Aubuchon Hardware site shows the piece. It's the black gasket (?) below the flange, that sort of cups upward. It's a separate piece from the large black rubber washer that goes up against the bottom of the sink. What is this for?

Thank you. I tried it, but it doesn't seem to work with the size and shape of the hole. But I'll know for next time.