Westone ER-9 Replacement Filter (Single) for ES49, 9dB, Blue;

Designed for use with the Westone's DefendEar Concert (Style 49) Musicians' Earplugs. Etymotic filters feature a flat frequency response that allows musicians to hear their performance accurately while providing hearing protection. The ER-9 provides flat 9 dB sound reduction through 2 kHz and slopes down to 15 dB at approximately 8 kHz. It is the ideal attenuator for musical situations that may not require as much attenuation as the ER-15 or ER-25 filters provide.