SD SeriesMATERIAL External Body is made of ABS. The internal interconnected clips are Nickel Plated or Silver Plated. CONSTRUCTION TERMINAL STRIPS Twin columns are aparted by 7.62 mm center channel. There are 64 groups of 5 interconnected contact sockets on each side. * SD Series includes SD-5D,SD-10,SD-11,SD-12,SD-12F,SD-24 and SD-35.If you are interested in this product,please download the PDF for more details.