The "P" value of an LED screen is the distance between two pixels in millimetres. The smaller the pitch, the higher the resolution — and the price.
The golden rule is viewing distance: a P-value roughly equals the comfortable viewing distance in metres. A P4 screen looks sharp from about 4 metres, a P2.5 from 2.5 metres.
We recommend P2.5 / P3 for shop windows and low facades, and P4 / P5 for high facades, roadsides and squares. Not sure? Book a free site survey and we'll size it for you.