These polished clear acrylic window brackets are the ones that are sold with our window garden shelves. You can buy then separately if you wish. THey are 3/4" x 3/4" in size by whatever length you desire. They come polished, with a #6 or #8 countersunk hole 1" from each end to be mounted on the top and bottom of each side of the shelf. You can use these also to hang a glass shelf to make it look like a lot cleaner installation. This listing is for up to 12" long for the straight brackets. Just state in the notes field the exact length that you need and we will make sure that is what you get. If the holes are not in the correct place for you then just include that information also. We have been asked quite a few times why 4 brackets per shelf. The answer is safety. That way if just a little too much weight is put too close to the front the shelf does not tip over into your sink dropping everything that is on it. It is a safety feature. The brackets lock the shelf in place with no possibility of tipping over. Even if there isn't anything that is too close to the edge, there is always the possibility of a tremor or a cabinet door slamming accidentally. Can you imagine all of your plants ending up in your sink or floor? Or worse, a treasure that you have had for years getting broken! This way the shelf is captured between two brackets and cannot go anywhere. Call 800.200.4228 if you need these made custom. Go to www.theplasticsmart.com to see some of our other products.