The present invention relates generally to testing and management of telecommunication networks and equipment. The water-insoluble polymer particles contain silica particles and a pigment other than the silica particles. Additional gelling agents may be added to increase support for the plant protein, enhancing the product’s texture. The light sources are respectively disposed on the first surface opposite to the high efficient heat-dissipating section and the low efficient heat-dissipating section. The cover comprises a first material suitable for installing the feedthrough subassembly and a second material matched to the case body for forming a reliable weld thereto.