The lid to the Fermonster PET carboy can be pesky to get off at times! Though it is a screw-type lid, they can be tricky and get stuck, causing sore fingers when you try with all your might to get the lid off. With the Fermonster Finger Saving Lid Opener, hurt fingers and frustration while opening the lid to your Fermonster are things of the past. Simply seat the opener over the lid and give a twist to the handles. That's it! Works for both solid and open lid styles on both the 6 and 7 gallon Fermonster models.