The Mylar buddy is a tool designed to help you seal bags with an iron and a bucket.  It has notches that allow it to fit comfortably on 1, 2 and 5 gallon kits, holding it in place while you use the flat side to lay the lip of your bag as you use an iron to seal it.  It works best with 2 gallon buckets and 1 gallon bags, but also with quart bags and a 1 gallon bucket, and with 5 gallon bags and 5 gallon buckets. The wood pattern and grain may vary from the picture shown.

You can check out the Youtube link below to see a demonstration!