Musician Earplugs - Custom Molds onlySoft silicone molds for Musicians Earplugs Note: This product is custom molds only for people who already own Etymotic earplug filters but need new earplugs to use them with. These ER Series Musicians Earplug Molds REQUIRE the use of Etymotic ER Series filters. First time earplug shoppers should check out our Sensaphonics ER Series Musicians Earplugs.