ER-3C insert earpiece, 300 Ohm from Etymotic Research

Set of ER-3C insert headphones, 300 Ohm with accessories by Etymotic Research
Advantages of the ER-3C headphones:
- touch-proof" electrical connection for safety.
- Same smooth frequency response as ER-3A
- Provides 30+ dB of external noise attenuation - equivalent to a single-walled enclosure when used with deep-sealed foam earplugs.
- Provides 70+ dB isolation (interaural attenuation) between ears; reduces need for masking.
- Reduces variability of tests and repetitions compared to supra-aural earphones.
- Eliminates test errors due to collapsed ear canals
- Simplifies real-ear-to-coupler-difference (RECD) measurements
- Can be calibrated in a 2 cm coupler, a closed ear simulator or a 0.4 cm coupler.

Includes: ER-3C headphones (300 ohms), 7" cable with dual mono 6.33 mm (1/4") connectors, 20 foam ear tips (normal, 13 mm), 20 foam ear tips (small, 10 mm), 2 foam ear tips (large, 18 mm), Velcro neck strap