It does act as a spacer to keep the spring at the correct height on the stem, but you can remove it and use the perc without the spacer in place, just be sure to place the spring at the same height on the stem. It is tight enough to remain in place without the spacer. I've used my Farberware Percs without this spacer with no problems. A hint for cleaning your new perc, as they are usually pretty stained when you get one used. To get your new perc spotlessly clean,
1. Fill it to max level with tap water.
2. Put dishwasher detergent in the basket,(enough for 1 load of dishes, or 1 pak if using paks)
3 Run the pot thru a full brew cycle, then unplug and leave it for at least 1/2 hr.
4 Pour out the dirty water and detergent, rinse with clear water. You won't believe how dirty the water will be.
5. Now fill again with clean tap water and run thru another brew cycle, discard water, rinse and now you have a sparkling clean perc that will look brand new,
Repeat this process when ever your pot needs a good cleaning again.
Eddie