MSA/Sordin Silicone Ear Seal Set:
Silicone filled Ear Seal (AKA "Hygiene Kit"), fits MSA/Sordin Supreme Pro, Supreme Pro X, Supreme Pro 3+ Hearing protection.  Each kit includes a set of silicone filled ear rings and a set of foam muff liners.  The silicone filings provides more comfort and a softer fit over the standard foam ring.  They also provide a closer fit so they seal better over glasses and headgear.