About this 3D model

I created this because they are so expensive to buy and the ones available for 3D printing tend to be too big for my printer. I rarely bind larger than A5 so why have anything any bigger. I also wanted a small magnet in the end to keep everything in place and lined up. The magnets I used are available at Amazon: https://www.amazon.co.uk/gp/product/B097MJLY51/ref=ppx_yo_dt_b_asin_title_o06_s00?ie=UTF8&psc=1