Magnet Counterparts. Basic plated steel discs, designed to complement the RS Energise to Release and Energise to Hold magnets. ; 739-3264 739-3264 : 25mm Dia ; 739-3211 739-3211 : 30mm Dia ; 739-3255 739-3255 : 40mm Dia ; 739-3251 739-3251 : 50mm Dia ; 739-3217 739-3217 : 65mm Dia ; 739-3214 739-3214 : 80mm Dia