Adafruit like capacitors so much they have made a kids show about them. They're super handy and it's really helpful to have a variety lying around to pick and choose from.
This is a 10 pack of 47uF 35V capacitors so they can be used with any DC voltage up to 35V. They have a tolerance of ±20% and long flexible pins that make them great for perf or breadboards. Remember that electrolytic capacitors are good for low frequency filtering (~1KHz or less), for higher frequency, pair up with a ceramic capacitor