Protect your spare propellers from bending and disfigurement. This case made from PLA (a non-transparent material) , was designed with size and portability in mind. Now you can carry your spare propellers around without worry of damage. This can throw off the balance of your propellers resulting in decreased performance and vibration. The low profile box has two stack posts to help keep everything secure. Simply slide one propeller on one post and one on the other post and repeat alternating. The top was designed with side wings for easy opening. Carries 4 propellers (NOT INCLUDED).