1" Black Aluminum Screw Post Extensions are aluminum posts having a male thread at one end and a threaded hole at the other. They have a #8/32 thread and are 3/16" diameter. They are used for extending the length of our aluminum screw posts. The post length is 1". Post length is the length that the extension will add to the screw post it is assembled with. These extensions will fit aluminum screw posts that are 3/8" long or longer. They will thread into the shorter posts, but the screw threads will protrude slightly. They have a black anodize finish to give you that wonderful shiny look and are as sturdy as regular aluminum posts.