The slide-in T-nut with holding spring is a fastening option that is compatible with the 80/20 metric 45 series and loads from the profile ends. The projection on the T-nut aligns it in the T-slot while the spring holds the fastener in place, even when the profile is in a vertical position. The spring is removable and snaps onto the threaded projection.
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/.