Etymotic ResearchER-15 Single Filter for Musicians' Earplugs™ (Clear)

Etymotic Research ER-15 Single Filter for Musicians' Earplugs (Clear)

Etymotic Research® ER-25 Single Filter for Musicians' Earplugs™ (Blue)

Etymotic Research® ER-9 Single Filter for Musicians' Earplugs™ (Red)