Looking at some radios

Looking at some radios

any #cassette tape deck nerds know what kind of belt I need for a Unitra Finezja 1 (M 536 SD)
got it from my grandpa n it seems to work fine the belt does need a replacement though probably
(I also need to get a 5-pin DIN to RCA cable cuz I have no clue how good the audio quality is n I don't think my grandpa's old stereo has the best amp/speakers)