Easy configuration: easily add this extension to the Cardinal Gates - duragate (item model number: MG25) Adds needed Height: this Height extension adds an additional 8" Of height to your gate. Use up to two tpx extensions on one gate. Disclaimer: sold separately. Attach the extension to the pet gate as directed. Doesn't work with other brands. Only fits the Cardinal Gates duragate. For pet use only. International products have separate terms, are sold from abroad and may differ from local products, including fit, age ratings, and language of product, labeling or instructions.