The guards give more strength to the Phantom arms where the motor screws down. I used the prop guards for a couple flights but took them off as I found the P3 flies better without them. Anyway I got too close to my metal patio cover and the P3A didn't respond to my MC so it fell into the lawn from 9 feet high. I dug the dirt out of the guard and that was it, props were fine, it did hit hard enough to throw the battery 5 feet away from the quad but nothing was cracked and I have been on many flights since. The strength from the guards saved the stress on the motor where the arms seem to crack. I am sure the arm would have cracked at the motor mount area without the extended guards..
Reviewed by: Michael Callahan from Georgia.