I recently purchased a Phantom 4 Pro and I see that you offer 2 different propeller guards. Which one should I use for my drone? thanks

Depends on what your preference is, I haven't used prop guards since then P3 days. The P4P has so many sensors, that prop guards aren't a necessity as they were before

Aloha Curse,

     The larger propguards were developed for the P4 but they interfered with the forward sensors.  The newer version is a simple loop that orients to the side so it does not interfere with the sensors.  The new ones will not stop a forward collision and the blades will get damaged but the now functioning sensors are supposed to stop the forward (and backward) collisions.

     The new propguards now appear to supplement the sensors.  Except for flying in beginner mode and Tripod, the side infrared sensors do not operate.  So the side oriented propguards provide protection on the sides under most flying conditions.

     Both propguards are $19 and look slightly different with the older ones having a center support like the P3 ones.  The side orientation of the new propguards also helps keep the propguards out of the video when increasing power going forward.

     Hope this helps !

Aloha and Drone On!