Review on Dust Care Replacement HEPA Exhaust Post Motor Filter for Dyson DC27 & DC28 Animal, Compatible with Dyson Part 915916-03 by Barbara Gonzalez

I've made a few of these and they work great. I change them every few months although I know I can wash them. Please ask, does this white teflon ring go up or down? I can't get an answer from Google OR Duckduckgo. I'm pretty sure the original Dyson filter has the larger of the two plastic rims sticking up. It has no relief, no "salad bowl" effect on the side where there is a white Teflon/Kevex ring. GRATITUDE!