Pixel pitch size (PH) is a specification for a LED display that describes the distance between 2 pixels inside of a display screen.

Pixel pitch size may be measured in millimeters, with a smaller number meaning closer spacing. Closer spacing generally produces a sharper image (as there are more pixels in a given area).

Common PH sizes in RGB LED display are PH4(4mm), PH5(5mm), PH6(6mm), PH7.62(7.62mm), PH10(10mm), PH12(12mm), PH14(14mm), PH16(16mm), PH20(20mm), PH25(25mm) and PH30(30mm). There are some examples shown as below: