Lithium-ion batteries have greater life spans than their Ni-MH or Ni-Cad counterparts giving 430% greater run time. Lithium-ion's 40% weight saving means 18 volt power can be obtained by a battery that weighs the same as a 12 volt Ni-MH battery. 4 pole motor. Anti-restart function with warning lamp. Capable of using wheels or discs for mains grinders. Easy grip body. Electronic current limiter with warning lamp. High comfort grips.