The Beyerdynamic DT 990 Pro is an open-back studio headphone designed for professional audio monitoring and mixing. It has a frequency response range of 5 Hz to 35 kHz, providing an extended frequency range for accurate reproduction of audio. The headphones feature a durable construction with rugged metal headband and adjustable, soft padded ear cups for comfort during long listening sessions. The DT 990 Pro has a nominal impedance of 250 ohms and requires a headphone amplifier or audio interface with sufficient power to drive it effectively. It has a balanced sound signature with detailed highs and powerful bass response, making it popular among audio professionals and enthusiasts.