Walker's Nano Technology is a truly durable and invisible liquid repellent coating inside and out. One environmental adaptive listening mode, 40 dB. of hearing enhancement. All Elite series in ear models have the following features: 4 digital sound processing channels, 20 bit audio processor for crisp clear sound, 8 band graphic equalizer, Nano-Tech water repellant coating, automatic feedback control, 20 percent smaller than Game Ear series 1, toggle volume control, sound activated compression, low battery tone indicator and a NRR of 29db. Operates on a number 13 battery. Includes Walker's field carrying pouch.