I always jump at the chance to design and print something from scratch. So, the moment we received our order, I got to work. The parts are retained near the back with two thumb screws, and there is a ridge to keep them from falling out. In total, including hardware, the cost is less than $5.25. This is just the first prototype. I plan to make them clip in, removing the need for retaining screws. Additionally, I’m working on a way for the two halves to lock together, eliminating the need for machine screws, which accounts for one-third of the cost. Can’t wait to see it installed for a customer.