― I've been dying to get some of these tumbler lids since I saw them on Groopdealz May 3rd. After missing out on snatching up the deal, then shopping around the internet for them, I was discouraged, because they are ridiculously expensive!!! AND I couldn't find a tutorial on how the heck they were made. I knew they could be made on the cheap, just needed to figure out what that darn seal was! ∙ Materials Needed: ∙ Mason jar lid ∙ Seal or Grommet ∙ Drill and 3/8" drill [...].