Our tree supports are being used, tested and recommended by several universities, arboretums and foresters. Many well-known large commercial growers and garden centers use thousands of these supports to produce stronger, thicker and straighter trees for the consumer and landscaper. For the most part, these supports are not available in retail locations but may be also purchased through several reputable and respected nursery and garden supply catalogues or selected wholesale distributors. We have not listed some of our products in our on-line store since many are used primarily in commercial applications. The Tree-Mate-O and Tree Guard are used commercially as well, plus also make great products for you. We thank you for your interest in our products. If you have any questions about any of our other products, please give us a call at 1-877-854-5497 9AM-5PM EST Mon-Fri. Tree-L-C