The first step when ordering a clock insert is to measure how wide the hole is that the clock insert is supposed to go into.
Once you have this information you can view the clock inserts below and get one that will fit into the hole.
If the clock insert is too loose when you get it, you can put a rubber band around the back of the unit to fill up the space some.
No one will see the rubber band and it makes the clock inserts fit tighter.
When selecting the correct clock inserts you will need to choose the dial face color and then also Arabic or Roman numbers.
Roman numbers are the kind where 12 will be displayed as XII and Arabic would be displayed as 12.