Finder 3931 masterplus electromechanical relay interface modules finder 393182300060 this is the finder 393182300060 relay interface module from the masterplus range these are versatile electromechanical relay modules which can be used for either inputs to or outputs from plcs and other controllers they feature an led coil indicator an integral protection circuit plus a user changeable micro fuse 5 x 20mm which is visible through a window this module has an ac only coil finder