1" Gold Extensions are great for giving your book a little extra length. They are 3/16" diameter with a #8/32 thread size. You can use these extensions in all types of screw posts as long as they have a 3/16" diameter. The Gold is anodized onto the screw post to give it the wonderful shinny color. Extensions are great to use for scrapbooking, photo albums, color swatches, custom portfolios, and so much more. If you are using the screw post extension or a regular screw post make sure your hole is drilled or punched for a standard 1/4" hole.