In-ear headphones with a closed construction, weighing about 20 grams and 1.20 m long durable cable that can be replaced. There is a controller on the cable with an integrated microphone and controls for receiving calls or switching songs. A curved 3.5 mm jack connector is used for connection. 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 converter is more sensitive and has a better ability to reproduce details. The impedance of the NRA headphones is 25 Ohm and their sensitivity is 103 dB / mW. The headphones have an ergonomic design, so they fit snugly in your ear and the silicone attachments ensure that they will hold great.