... circuit for the polarity inside th1e device Standard 19/9.5 inches rack, little volume, light weight, steady capacity and convenient setup ... 19 inches rack, so the volume is little, weight is light and operation is convenient and credit. 4E1 fiber multiplexer, is ... . The 2M (E1) interfaces can connect with the exchanger, light loop device and multidiplexer directly to form the micromidi or the special ...