J-GUANG breadboard has three types: common solderless breadboard, transparent solderless, combination breadboard. They have two packing: box packing and tray packing, we can pack goods according to customers’ requirements. Specification Dielectric Withstanding Voltage: 500V AC(rms) For 1 Minute. Insulation Resistance: 1000MΩ Min Contact Resistance: 100mΩ Max. Initial Temperature Range: -20°C~+80°C Material Insulator: Thermoplastic