American Standard 735004 Color:Black It hardens to a consistency

It hardens to a consistency similar to automotive paint and is chemical resistant so you can clean it with normal household cleaners

We are not positive but believe the hole is used for some kind of locking mechanism

Lid Size: 18

In addition to offering any tank lid we've identified in these reproduction listings

Lid P/N: 2009 / 735001

American Standard 735004 Color:Black It hardens to a consistencyManufacturer: AMERICAN STANDARD Lid P N: 2012 735004 Lid Size: 20" x 8. 625" Tank P N: 2037 Tank Size: 19" x 7. 5" Toilet Model: Roma II One Piece This is also a Lexington toilet, often confused with 735025. Check to make sure you are ordering the correct one based on the photos and dimensions we have listed.