Features: Resistant to Humidity - Special flashhead connectors, security seals and caps, "Dry-foot" construction for wet outdoor-conditions. Power Stored - efficient 1100 w/s Charging - Fast - 6 seconds to full power for approx. 100 flashes. Slow - 11 seconds to full power approx. 140 flashes. Charger - Multi-voltage with set of three adapters. Re-Charging Time - To full power - 3 hours. The charger can charge a battery in the unit or externally. N.B. New batteries require several cycles to reach full efficiency. Charge Ready Beep - Switchable On/Off, with green LED indicator. Charge Ready Light/Open Flash - Indicated by two bright LEDs! Battery Charge Indicator - Two green LEDs 100%, one green LED 50%, and one red LED approx. 10%. The Free Style electronic monitors the low level charge to maximise battery life. Modelling Lamp - Press the touch once, modelling lamp will switch off automatically after 15 seconds to conserve power. Press twice (within 2 seconds), the modelling lamp will switch off only after 30 seconds. Maximum modelling lamp power is 100 W (one flashhead), 50 W (using two). N.B. 100 W modelling lamp power for 12 seconds equals one full power flash! Photo Cell - is adapted to release in bright ambient light. Auto Off - To save battery power and maximize flashes, the Ranger will always switch off 5 minutes after the last operation. Memory - Retains all last settings even at automatic switch off! Power Adjustment with ADF - 5 f-stop power range (68 w/s - 1100 w/s) in 1/10 steps with "Auto-Dump-Function". Synchro Socket - A traditional synch socket, used in all Elinchrom/Prolinca units. Battery-Box Quick Release - Press the pads on the left and right sides of the housing. Lift the unit to release the battery. Place the unit over the replacement battery and press down firmly. Power Display - Logarithmic, compatible with all other Elinchrom power displays.