I bought this thinking they were all different sizes but I'm all the same size! I looked again at Revain's product page and noticed that there is a drop down list and one of them says "6 - 2.2", 12 - 2.5", 12 - 2.75" , 6 - 3". ", " I didn't select that option. So I'm disappointed that all mine are the same size, but the good news is the product is still great. This is the ideal weight to keep the corners of the shirt down. My shirts really do feel better when I wear them and I've had a few comments about them since I've worn them. The moral of the story is, if you want to keep multiple collar sizes, order the correct one!The drop down option that says 6 is 2.2", 12 is 2.5", 12 is 2.75" and 6 is only 3"!