The finish Choices are As Cast or Polished.
Quantity of one adaptor is also listed
Use these to keep your valve covers top clean of holes. They bolt to the side of VC.
Use a rubber grommet 1.25 (commonly available in parts stores and Ebay)
Then any 1" breather can be used
Use of a 3/4" grommet allows use of a PCV
Here is what you need to do to seal them.
Use Ultra black RTV. Put a thin layer on the side adaptor. Less than 1/16 inch. Carefully insert a bolt thru the adaptor. Allign the adaptor to the bolt pattern on valve cover. Lay it down and start the bolt. Start the second bolt. Snug both bolts down. Do not tighten, yet. Wipe away excess RTV. Let the RTV cure. The next day, remove bolts and apply RTV to the threads and reinstall the bolts, now fully tightening them. You should be leak free. Far superior to gaskets.