The ZG-203 consists of three chambers, each made of 0.025" [0,64mm] MuMETAL® and is designed to attenuate external static and low frequency A.C. fields up to 2,500 times. Each of the three magnetic shield layers consists of a cylinder with one closed end and one open end (access opening). A close-fitting, removable cover is provided on the access opening end. Of all geometric shapes, a cylindrical configuration is one of the most effective for absorbing external magnetic flux lines, thus creating an efficient magnetically shielded finite space.The standard model ZG-203 has an inside work area measuring 3" diameter X 9" length, and is universally designed to solve most application requirements, however, custom sizes and configurations can be quoted to your exacting specifications.Suggested optional accessories are a Degaussing Coil for reducing residual magnetism and a matching sized Cradle to hold the chambers in a stable position are both available upon request.NOTE: Ask about our custom sizes and configurations that can be manufactured to your specifications. Contact us now.