I purchased 3 ND/PL filters in a kit directly from Polar Pro and found some kind of Residue or Adhesive on the Frame of all 3 and some on the surface of one of the filters. I contacted Polar Pro about this and there response was rather shocking! They said it was normal for the Foam In the case to stick to the filters sometimes! and it’s not a big deal! just to clean It carefully! (This Stuff is Really Sticky could cause the filters to get scratched if dirt was caught in it!) and the same with the surface of the filters. Do they not take the way they packaged their products seriously! These are supposed to be the best of the best! The case they designed to protect the product should never leave a residue on the product! I have lots of Filters for my Pro DSlR equipment and none of the manufacturers would ever tell a customer the case may require you to clean the filters before each use! I purchased their product because they had the best overall reviews and seemed to make the best products for drones but if they can’t make a case to safely store the products and keep them clean especially from the case itself! There’s a problem with PP! These things are not cheap I have 67mm filters for my DSlR’s made of much better materials that cost less! After their “Just Deal With It” response I think I will be looking for another manufacturer of Mavic Accessories.