ACRYLIC SPACERS / ADAPTERS: These are acrylic mounting plates. The term "spacer" comes from the fact that they are often used to create non-metallic "space" between a proximity card reader and metal to improve read range. Spacers may also be used to attach one or more components to a pedestal flange. While they do not provide the top and side weather protection of a steel housing they are often an attractive alternative, especially when proximity card readers are involved. The basic part number format for a spacer is AMBxxx-MS, where AM = Acrylic Mounting Plate, B is the first letter of the component brand, xxx is the component model number and MS is the Mounting Style. Multiple HPBxxx terms are used as required.