I have several types of sealant that I use from time to time. They prevent the sealants from drying out. One day I use some sealant and then I put this cap on. I'll have to use it again in a few weeks. When I remove the lid it works so well that I do NOT have to remove any dried clogs from the spout. I've tried a few different brands now, this one works best for me and the price is very reasonable. I don't recommend them to people who are tired of throwing away partially used caulk tubes because they dry out prematurely.