This is a 100 Farad capacitor. Combine two in series for 50F/5.4V. Our testing told us that two of these can power Arduino for 4 hours (with one LED). And you can recharge the capacitor just within 30 seconds. It can be used in Electric toys, wireless modems, motor drivers, portable terminals, duplicators (rapid heating), car audios, remote controllers (self-electric charging), AMR(Automatic Meter Reading), uninterruptible power supply(UPS), electric valves, actuators, wind velocity(pitch control), alarm/security devices Warning: Do not over voltage or reverse polarize these capacitors. Specification: Rating Voltage:2.7V Capacitance:100 Frad Rating output current: 1A Maximum output current:>60A Leaking current:0.28mA Max. Internal Resistance:10 mOhm Voltage Under 24 hours charging:2.4V 500,000 cycle life (semi-permanent) Size:22x45mm(0.87x1.77")