This listing is for a VINTAGE SONY WALKMAN CASSETTE PLAYER WM-2. The center gear wheel is not cracked, it is either the original or was replaced, I am not sure exactly but it is not cracked. Sold as defective because it has some fluctuations in sound when playing,  they might disappear with use or might need some further checking and fixing, apparently this model is very sensitive about the belt and if you could find a suitable belt then the fluctuations might be reduced a lot, that is what I read online but I am not sure as I have not tried that myself. Also the small battery cover inside the walkman is missing but it will work without it, that cover can be bought on ebay for around $20 or something.

This walkman has a standard jack so many different brands of headphones can be plugged into it. 

This walkman uses two standard AA size batteries for power.