Self-tightening Props Balancer for DJI PHANTOM

• 3mm shaft applied. The thinner the shaft is, the higher the accuracy (also cost higher to build).
• Come with two pieces (a pair) per package: one is black for CW and the other is silver for CCW.
• Place on two parallel edges to do balance.
• Applicable to Phantom 1 / 2 / 3  self-tightening props. 

• Make sure the tool is seating on two level, straight, and solid edges (such as two pens in the same type, top of a glass).
• Must be absolutely no wind. Even a breath can affect the result.