My daughter was complaining about having a bunch of coins clutter and fall out of her little purse, so my solution was this coin purse. I am honestly surprised it worked the first time and without redesign. I am open to suggestions and will redesign if anyone wants a redesign. You just pull on the tab a bit to open and close. I printed this in TPU. I would assume any flexible filament will work, like ninja flex. Design files from Brink Effects are provided for your reference only. By downloading the files, you assume responsibility to verify the design for your use and safety. Brink Effects cannot control how the files are used; thus Brink Effects does not hold any liability for the use of the files. Use at your own risk. Remember to keep small objects away from children and pets. Be cautious of sharp edges.