[tyingq]

"HUB75" refers to the 16 pin connector and specific structure of the square wave signals it's expecting (row order, pixel order, etc). This particular sign appears to use a 4mm pitch (space between each R/G/B led), indoor-level brightness SMD leds, and modules that are 32x64 pixels, like this one on AliExpress: https://www.aliexpress.us/item/2251832064290423.html?spm=a2g... ( ~$8 + ~$9 shipping to the US for single qty).

There are various "HUB75" panels of different pitch, brightness, LED type, matrix size, etc. Also, there's variations like "HUB75E" with 5 address lines instead of 4. Address lines are typically A/B/C, A/B/C/D, or A/B/C/D/E. And there's also "HUB08", "HUB12" and other standards.