Hight power defense device 1.Hight frequency circuit adopted to improve capacity of DC 地上charge the output power is 5 times more than that of the impulse design. 2 Delicate and fashionable design 3 If you feel unsafe while walking, running, hiking, or when you’re outside, the Blast Knuckles are a great option! Specifications 1.Source voltage:3.6VDC 2.Current:＞2.0A 3.Output pulse voltage :200KV 4.Weight:60G 5.Size L58mm XW24mmXH76mm How to use: 1.Before using.it should be recharged 6-8hours with the equipped charger,(charging method:put the charging wire end insert the charging interface,put the nest end insert the 110vpower then it is charging,when the charge indicator light turns to be red,its normal charging, when red light turns green,its fully recharged,) 2.Push weitch up till the red LED indicator light on and press the shock sweitch.it's shocking 3.After a long period of non-use (longer than two months) it should be recharged and fully checked. 4.To extend the life of usage,please avioid continuously using electric shock function for more than 10 seconds.