As a thickness measuring sensor and controller designed to stabilizes thickness of molten plastic layer of plastic blow and molding machinery. In continuous molding processes, EOS measures output film thickness of extruders and balances the temperature distribution in different zones, aims to keep output layer within constant thickness range under different viscosity conditions. In batch molding processes, according to the dimensions and body pattern of the product, EOS changes the thickness based on programmed profile along the layer resulting unique thickness in the final body after molding. Various analog and digital outputs are implemented and programmed to control hydraulic actuators of the molds and heaters power. Optimized design, ease of integration and operation, as well as reducing waste and increasing the quality of products are the advantages of EOS.