The Akai GX-F 31 is a cassette deck produced by Akai, a Japanese electronics brand. It was part of the GX-F series of cassette decks that were introduced in the 1980s. The GX-F 31 features a front-loading mechanism, Dolby B and C noise reduction systems, and adjustable recording levels. It has dual auto-reverse capability, allowing for continuous playback without manually flipping the cassette. The deck also has features like auto tape type selection and tape bias adjustment. Overall, the Akai GX-F 31 is a cassette deck known for its reliability and functionality.