4 pack of PC + glass fiber propellers. (2 CW, 2 CCW)
These props are also known as the "Surveilzone Unbreakable Props". They are not unbreakable, but they are very durable.
Inner diameter (Prop Mount): 5mm
Throttle feel is much more even/linear and accurate. Grip, response and 'whisp' qualities are about the same and durability is definitely improved. Control is drastically great, more linear thrust delivery, the pitch/roll feel far more even and stable throughout the throw of the sticks regardless of your rate/expo set up.