The wristwatch includes a bracelet or strap, a plastic case including a case middle-bezel, a watch crystal, a back cover and two pairs of horns to which the two ends of the bracelet or strap are respectively attached. According to the chip testing apparatus and method, the fault that may be overlooked during the chip fabrication process can be discriminated, and thus a stable chip can be provided in implementing the whole system. A hydrophilic filter canister is received in the housing filling the reservoir. The organic light-emitting diode exhibits high current efficiency, high power efficiency and long lifetime when compared to conventional devices using BAlq.