A wire twisting tool is provided which is adapted to be used in the installation of wire ties that are used to support a building ceiling, or other ceiling components such as piping, HVAC equipment, or the like. The light-emitting device includes a substrate, and an n-cladding layer, an active layer, a p-cladding layer, a grid cell layer and an ohmic contact layer sequentially formed on the substrate. As these strip 204 have a relatively large heat conductivity, a large proportion of the heat that would otherwise drive heat flows 111, 112 is dispersed and does not therefore cause inaccuracies or bias in the measured flow rate. The value K may be selected such that 2 is an odd number. The method includes transmitting video of the first person to the wireless handheld device of the second person, transmitting audio of the first person to the wireless handheld device of the second person, and transmitting audio of the second person to the first person at the entrance.