This was actually a 20 25 1. I am very pleased, in the morning I always wake up with a semi stopped up nose. The first morning like clock work, use the restroom, blow my stuffed up nose. I couldn't believe it, my nose wasn't stopped up. My dog has breathing problems, when the air cuts on at times she has problems breathing, no more it has been such a relief. I didn't realize how drastic an improvement it would be, thank you.