Plastic “collar” around base of lightbulbs: keep or discard?

First time I’m seeing this plastic piece on lightbulbs I just purchased. I don’t have a picture of the specific bulb I’m referring to, but this is the closest I could find:



The plastic “collar” is located at the top of the metal base and lower part of the “glass” bulb.

Does anyone here know what it’s for and if it should be kept or discarded before installation? It doesn’t seem to interfere with the connection and the lights still work. I’m more concerned about the heat generated from the bulb melting this piece.

I can’t seem to find any info on it.