Remington 1100/11-87 Barrel Seal. Teflon. Improves Reliability & Function. Remington factory gas system seals keep 1100s and 11-87s functioning their best.
There are aftermarket seals out there that many use and from my expirience with these guns I can say they work but will not last aslong as the Factory part. I have competition shooters bring their gun in and the guns have the same barrel seal that came with it thousands of rounds ago. I guess my dad said it best as he always said " Buy cheap and you buy often".