The 10S464 was one of Zenith's most popular radios for 1940.  It features a large black dial, green tuning indicator, 'radiorgan' tone controls, pushbuttons, 3 bands and push-pull audio output.  The tuning knob is weighted, and the chassis is mounted on springs.  Overall performance was very good, and with the popular streamline modern styling, there's no wonder why it was such a sales success.  This model was one of the first to use some photofinish (the front of the grill bars).  In general, mine is in very good condition, but often these radios are found with the photofinish completely worn off.