The Magnet Screwdriver Kit Is Very Suitable For Small Screws In Smartphones, Tablets And Precision Objects It Works Through Charging, As It Needs A Full Charge For 30 Minutes, To Work After 180 Minutes No Sound Of Screwdriver For Rotation A Display Screen On The Screwdriver Showing The Amount Of Charge + The Hand Of Winding The Screwdriver And The Screw Made Of Cr-V Steel, After High Temperature Processing Process There Are Two Buttons To Control The Screw Twist To The Right Or Left Battery Capacity : 350 Mah Available In Light Grey