What is giffgaff Always On data?

What is giffgaff Always On data?

With Always On* you get 20GB of data usage per month at full 4G speed. After 20GB of data used you’ll experience a reduced data speed of 384kbps from 8am to Midnight. You may notice that activities which require high amounts of data, like HD video streaming, will be slower. From midnight to 7.59 am you’ll have a data allowance at full speed.