Whilst feather light and an absolute joy to work with, the Pocket Flag will not work with a string and will not sustain any impact - the Pocket Stick can carry a string and sustain light tapping as required by horsemanship exercises requiring direct rhythmic pressure.
The Pocket Flag retracts from the bottom up by bumping the pieces gently - the Pocket Stick retracts more rapidly by pushing on the tip with your hand.
If you are not a patient person or are hard on tools, I suggest the Pocket Stick. Both tools are non-refundable and are not warranted for breakage. You shouldn't hit people, horses or objects with them, it is just not nice.
The Pocket Flag must be used extended to its full length. The Pocket Stick, by contrast, can be used at any length and will "lock in" where you adjust it to