820pF, 50V Ceramic Capacitor, replacement for original styrene audio caps in Atari consoles.
A likely failure point for a no-sound condition on Atari 2600 and 5200 consoles.
Original styrene caps in 820pF are getting hard to find, but these ceramic replacements will be lifetime components.
Atari P/N: CO10821
From the 2600 FSM Atari Technical Tips section:
On Audio Failures the primary suspects are the two polystyrene caps C206/C207. By putting pressure on the sound caps the audio may come on again. Always replace both caps when you replace one.