Meet the Jova Transformer Nixie Tube Clock: a modular clock with IN-18 tubes that can display the time and date in 3 modes. It has a gorgeous wooden base and a magnetic frame. You can attach and remove the Nixies without a whole lot of effort.
This clock has 12/24 hour mode. It has a RTC chip to keep time accurately. This particular module has 6 x IN18 Nixie modules.