Come with back cover and rubber gaskets to secure the insert in place, which can prevent slight irregularity in the hole. It can be used directly or embedded into clocks, hardware clocks, iron clocks, lighting-clocks, etc. Great for DIY crafts or replacing old clock face, and the clear cover reads the-time easily. Suitable for all kinds of crystal, ceramics, marble and other crafts table clock Quartz clock insert features a golden/silver colored trim, and black arab numerals for easy-reading.