POWERFUL JUMP STARTER 4000A/20000mAh: The 74Wh portable lithium car battery jump starter can safely jump start a low volt,drain or dead car battery in seconds with this 4000A car starter, rated for gasoline engines up to 12L and diesel engines up to 10L. Can work at -4ºF~149ºF extreme environments for Passager,Truck, Garden tractor, Generator, lawn Mower, Farm tractor, Riding mower, Motorcycles, Boat, Snowmobiling, ATVs, RV, Van, SUV, Watercraft, Yacht

BATTERY JUMPER STARTER PROTABLE: Compact size and lightwight (8.6"x5.5"x3.5",0.9lbs), easy to use and carry,can be storaged easily in the glove box of your car, safe and space-saving; comes with a storage box for the battery pack, car accessories are not easy to lose,also protects the car jumper from missed-touch

MORE THAN A CAR BATTERY JUMP STARTER: More than a car battery jump starter, the BOOKOO A9 designed with 2 USB outputs (5V/2.1A)and (5V/3A 9V/2A 12V/1.5A);The quick charge 3.0 USB port can fully charge your tablet, smartphone, GPS, camera, camcorders, Bluetooth headphones and other mobile devices at the fastest (up to 75% faster than a standard chargers)

MULTI FUNCATION JUMP BOX: Not just a jump box, it has 3 LED lights modes: Flash Light, Strobe Light, and SOS Light. This multi-purpose flashlight comes in handy in case of picnic, travel, emergency and outdoor adventures; 400LM 5W LED can work more than 10 hours,weather you take it for reading or for help

RELIABLE & 8 SAFE FEATURESL: The BOOKOO A9 jump starter 4000 A is super safe to use with 10 protections including: over-current, over-load, over-voltage,over-charge,short circuits, reverse polarity, power surging and sparking,and so forth; You can detect the errors by simply checking the lights and the beep sound from the smart jumper clamps.

LONG LASTING & LARGE CAPACITY: This A9 jumpstart was used a premium lithium-ion battery pack, 20000 mAh large capacity battery backup can start dead battery over 50 times and recharge your iPhone 4x, watch 10x, headphones 15x, suitable for more on-the-go devices; 18W Type-C input and QC 3.0 output allow you to power them up any time any where

IP66 WATER RESISTANT FOR EXTREME WEATHER: BOOKOO Jump starters fitted with a waterproof rubber stopper, allows you to start your car in raining or snowy day; And it can work easily at -4ºF~149ºF temp weather you are in California, Texas or Florida

WHAT YOU GET: A9 Jump Starter, Smart Jumper Clamps,USB Wall Charger Adapter, Micro USB A to USB C Cable, Hard carrying case, User Guide, lifetime technical support,24-month warranty and worry free after-sale service 24/7