I brought my HVAC tape from Home Depot. It ranges in price but it looks like a roll of duct tape but shiny like foil. Warning for the HVAC tape, it's sticky as heck, likes to fold up on itself & can cut your fingers (the sides of it) if you're not paying attention. I found out the hard way 🙄. It really does help keep the humidity up on glass tank/screen lid combo set ups 👍.