They worked great for securing our 4x4 square fence post to the 2x4 boards for extra strength and stability from the inside of the fence. Our actual post size is a little 3 1/2 inch, not quite 4 but these fit perfect. For anyone wondering, the lip part is a little over an inch so is flush against your 2 x 4 that you are attaching it to but attaching these on each 2x4 on your post will help tremendously during high winds being you secure your board or panels from the outside to your posts. So we have 3 on each post but for all the hard work of building and staining the fence it's worth it to hopefully make it last as long as possible. We live in Florida and being from Louisiana or any hurricane prone area this is a must unless you want to take a chance of your fence possibly laying flat on the ground like I have seen so many do after a storm. Now they are galvanized steel so if you want to paint them to blend in with your fence then you have to use something to make the paint bond to galvanized steel. So after much research, we learned that Rust Oleum Universal "bonding" primer first, let dry and then paint the color you want with a metal suitable paint. If you don't do the first step then your paint will will just peel right off. We painted ours and used stainless steel hardware and then gave the hardware a quick spray after installed to blend in. I attached photos to show before and after but fence feels super sturdy now!