Abstract: An electric tool includes a fastening unit, a control unit, a sensor unit, a communications unit, a storage unit, and a portable tool body. The sensor unit measures at least fastening torque applied by the fastening unit. The communications unit transmits operations data about a result of measurement made by the sensor unit. The communications unit includes a wireless communications unit and a wired communications unit. In a wireless communication mode, the wireless communications unit transmits, by a wireless communication method, at least a part of the operations data, when a fastening operation has been done for either one round or multiple rounds. In a wired communication mode, while the communications unit is operating in the wired communication mode, the wired communications unit transmits, by a wired communication method, the operations data stored in the storage unit.

Abstract: A novel lithium-manganese oxide composition suitable for use in lithium secondary batteries as an active material for positive electrodes, said oxide having a spinel type crystal structure, an Li:Mn molar ratio of 0.9-1.10:2.00, a mean Mn oxidation number of 3.40-3.60 valencies, and a BET specific surface area of at least 1 m.sup.2 /g, substantially all the primary particles of said oxide being less than 1 .mu.m; a process for preparing such an oxide and a lithium secondary battery containing such an oxide are also disclosed.