The MK 235 cassette recorder (sometimes referred to as “ZRK MK 235” or “MK 235 Automatic”) was manufactured in 1976-1978. The portable cassette recorder, positioned on the boundary of popular and standard product classes, was designed to record sound and play back recordings. Its design was based on the licensed C-235 model by Grundig. It incorporated transistors and an integrated circuit. The MK 235 is powered from an AC source or batteries (five R14 type batteries). Operation time using batteries is about 14 hours. The tape recorder is designed to play cassettes at a tape speed of 4.75 cm/s. The aesthetics of the device are minimalistic, dominated by the geometry of its overall shape. Its form is livened up by the rounding of its edges, using geometric shapes and grooves to divide the planes. Manufacturer: Zakłady Radiowe im. Marcina Kasprzaka, 1978 Inv. No.: MIM 1317/V-295 Model prepared on the basis of photogrammetric measurements Licence: CC BY-NC-SA