XINGYHENG 2Pcs 8 Channel Relay Module With the light coupling 12V Relay Expansion Plate Load Controlled Relay Switch Module Supports AVR 51 PIC Relay Control Module auspowers_batchfour These are:durable (thanks to premium sold2024 These are:durable (thanks to premium brass construction)resistant to corrosionsoliddo not leakhave a better thermal conductivity and a low magnetic permeabilitydon’t deform with timeprovide tight sealing thanks to the relative softness of brassare easily installed or changed (thanks to the hexagonal head that increases the bearing surface when a wrench is applied to the fitting)WHERE TO APPLY the cable will be tightly fixed but no need to disassemble Package include: 2pcs relay module small driving current at the input end can easily interface with computer terminals and various digital programmed circuits