In general, in one aspect, the disclosure describes an apparatus for shifting a low swing signal. This joiner is designed such that the adhesive force between the sealing material and the surface region of raised portion of the joiner is minimized, thereby making it possible to prevent the sealing material from being cracked or peeled away. A numeric digital display is provided on the top of the enclosure and reflects the current number of discharges or killed insects. The particle size of the nanosized EuSe crystals can be manipulated by the heating condition, thus the absorption wavelength of the EuSe crystals can be easily controlled. The received number is used as identification code of the respective network device.