This clock insert front diameter is 90mm/3.54in, back diameter is 78mm/3.07in, mounting depth is 15mm/0.59in, please check the size carefully before purchasing. clock insert features a golden colored trim, and black roman number on for easy reading. Come with back and rubber gasket to securely hold the insert in place, which can avoid slight irregularity in the hole. Great for replacing old clock and the clear reads the for time easily. Suitable for all kinds of crystal, ceramic, marble and other table clock wall clock.