Nordmende Discocorder RK-4186
The Nordmende RK4186 (model number 981.115H) is a re-styled JVC RC-838. It's exactly the same size, it contains the same JVC speakers, and it has all the same features including Biphonic. However, unlike the JVC, it has FM station presets, and separate Left and Right volume sliders.
It measures 506 x 320 x 145mm, and it weighs 7.5 KG (not including batteries). According to the service manual, its power output is 2x6 watts.