Electrolytic capacitors are really handy to have laying around. Typically these are used for surge suppressing / transient voltages / filtering out noise at the ~1KHz or less. This specific capacitor is rated for 1000uF and 25V with a +/- 20% tolerance. These capacitors are polarized and should not be hooked up backwards. The negative is denoted by a white line down the side of the capacitor with a negative symbol.