Nixie tube and seven-segmented displays have been around for decades, and the later has been utilized since the early 1900s and most used incandescent filaments housed in vacuum tubes. It wasn't till the '70s until the displays adopted LCD and LED technology, similar to the ones on the market today. They've also made a resurgence as of late, being widely implemented in a myriad of different projects that range from retro-styled clocks to electronic sudoku games.
Most seven-segment displays are on the small side, measuring around an inch or less relative to the digit size per segment, which is great for some projects but limits others. By contrast, maker Sawaiz Syed has developed a 16-segment version that measures in at a massive 100 x 66mm (4 x 2.5 inches), which communicates over a serial port for those requiring a larger display for their project builds. Syed says his Klais-16 display was inspired by those found in old cigarette machines, electronics equipment, and pinball games, and it's easy to see why.
Syed designed the Klais-16 using a three-layer approach, based on stacking layers to provide clearance, diffusion, and encapsulation for the electronics. The result is a modular alphanumeric display that is larger and thinner than what can be found on the market. It's driven by Titan Micro's TM1640 LED drive control circuit as well, so multiple displays can be linked together to create a larger board that functions in unison.
Syed has uploaded an incredibly detailed walkthrough of his fully open source Klais-16 16-segment display on GitHub for those who would like to recreate his build; otherwise, they can be purchased as a complete unit here.