Atdec 400mm Stackable Post SilverAWM P40X is a stackable post that enables the backbone of AWM family solutions to be extended to double length, and reduced to single post length, without disassembling the solution and replacing parts. AWM P40X is a specialised version of AWM P40G. The AWM P40X post is 400mm (15. 75") and supports virtually unlimited configurations of monitors in a single layer. A second AWM P40X can be attached to the original post without disassembly or removal.