Etymotic Research ER-4P

This is the real deal!!!!  Original, Unopened!!

The ER-4PT microPro In-Ear Stereo Headphones from Etymotic Research provide professional-quality audio in a lightweight and comfortable design ideal for traveling professionals. The headphones use ACCU·Driver balanced armature drivers to produce detailed, realistic audio with better than 86% accuracy from 20 Hz to 16 kHz. The drivers are precision matched and custom tuned, and also deliver extremely high output sensitivity. The headphones come with an industry-exclusive channel-matching compliance graph that's signed by the Etymotic engineer who matched and tuned the drivers.

In order to provide the best fit for comfort and noise isolation, the headphones come with 7 different types and sizes of interchangeable eartips. Using the proper eartip creates a seal in the ear that provides up to 98% (35-42 dB) noise isolation, and also reduces the risk of listening to your audio at unsafe levels. In addition to the supplied tips, a separate CUSTOM·FIT option lets you enjoy fully customized eartips.

The headphones are designed with lasting durability, and feature a braid-reinforced cable for extremely low microphonic effect. The cable has a gold-plated 3.5mm stereo mini plug and a 1/4" adapter is included for use with a variety of consumer and professional audio devices. Replaceable ACCU·Filters protect the headphone drivers from ear wax and other debris. Other accessories include a filter tool, shirt clip, travel pouch, and storage box.

Lightweight and compact design, ideal for travel
ACCU·Driver balanced armature drivers are precision matched and custom tuned to produce detailed, realistic audio with a high output sensitivity and better than 86% accuracy from 20 Hz to 16 kHz
The headphones include an industry-exclusive channel-matching compliance graph that's signed by the Etymotic engineer who matched and tuned the drivers
The headphones come with 7 different types and sizes of interchangeable eartips to provide the best fit for comfort and noise isolation
Using the proper eartip creates a seal in the ear that provides up to 98% (35-42dB) noise isolation, and also reduces the risk of listening to your audio at unsafe levels
In addition to the supplied tips, a separate CUSTOM·FIT option lets you enjoy fully customized eartips
The braid-reinforced cable offers lasting durability and extremely low microphonic effect
The cable has a gold-plated 3.5mm stereo mini plug and a 1/4" adapter is included for use with a variety of consumer and professional audio devices
Replaceable ACCU·Filters protect the headphone drivers from ear wax and other debris
Other accessories include a filter tool, shirt clip, travel pouch, and storage box