This is a Hanging ring I made I needed it strong and lockable once in place. I set it up to glue the collar for permanent mount but I could also design the slide to latch, if you find you want that please ask. It measures 109.2mm and the diameter is 12.5mm or 4.2inches and just under half an inch in diameter. Scale if you like for your preference if you need a smaller application, could easily be used for shower curtain rings and a hundred other places where one would want a ring keeper....