Good, but shipping cost is too high if we buy more than 2 pieces.
Nice little magic helpers:) Full compatibility with my Etymotic ER-4. Much better then overpriced stock single use plastic green filters. With red ones (2500) my ER-4 become much darker sounding, perfect for some heavy music. But with green ones (1500, as in stock filters), they better with jazz, but more sensitive to track quality.