Rubber band mounting systems: equipped with rubber band gasket/shrapnels to securely hold the insert in place, which allows for slight irregularity in the hole Wonderful gift,sweet warm friend family and yourself minis quartzs clock insert good for making or replacing clock faces Dimension: the overall diameter of the clock insert 2.56inches/65mm that refers to the front face outside maximums diameter including the colored bezels Suitable appearance design: three hands with arabic/roman numerals on dials allow for easy reading