In-ear headphones with a closed construction, a weight of about 20 grams and a 1.20 m long durable cable that can be replaced. On the cable there is a controller with an integrated microphone and controls for receiving calls or switching tracks. The bent 3.5 mm jack connector is used for connection. High-quality music reproduction is provided by a 10 mm dynamic transducer in combination with a 6.8 mm electret electrostatic transducer, which is based on the opposite principle of electret microphones. The electrostatic transducer is more sensitive and has a better ability to reproduce details. The impedance of NRA headphones is 25 Ohm and their sensitivity is 103 dB/mW. The headphones have an ergonomic design, so they fit perfectly in the ear, and the silicone tips ensure that they hold well.