The so-called 'unbreakable' props. These are made from a very soft compound that gives resilience in crashes.
This size prop is appropriate for 1306 3100kv motors running 3S and 4S. Also ok for 1306 4000kv on 3S. A bit wimpy for a 220x size motors that run lower kv.
Contains 4 props (2 CW, 2 CCW)