What do the ATLAS and KSSU Airplane Trolley Standards Mean?

Worldwide, there are two airplane trolley standards – ATLAS and KSSU. 

At first glance, they’re almost twins, yet they differ in detail: Both are about 103 cm tall and 30.5 cm wide, but they are worlds apart in depth! ATLAS measures about 40.5 cm, KSSU about 42.5 cm. For Full Size, it gets doubly interesting: ATLAS comes to about 81 cm and KSSU to about 85 cm.

But be warned: ATLAS accessories sulk with KSSU trolleys and vice versa. Tobias explains it in more detail in this guide and video. Got everything squared away?