The double-keyed UniBearing pad is commonly used with a UniBearing to create custom bearings. It has a double key and mounts to the profile using stainless steel flathead socket cap screws. It provides a flat bearing and quick change-out as well as being designed with rounded corners on the molded pad for easy installation.
For technical details and images, please search for the product using the 80/20 interactive catalogue found here: https://catalogs.8020.net/80-20-Catalog-26/C/.