This is a two part rubber duck cap for your Stanley or other tumbler or cup. The part that covers the straw and is designed to be printed in flexible TPU (use the “StrawCapV3.3mf” file or the “StrawCapV3.stl” file or print it directly from MakerWorld or the Handy app here: https://makerworld.com/en/models/488111#profileId-400979).

The rubber duck is designed to be printed in PLA or PETG with a 0.4mm nozzle, though I've also included a profile for a 0.2 mm nozzle if you want more detail. The profiles are made for use with an AMS. Once both pieces are printed, simply glue them together, and you've got yourself a fun and functional straw cap! I used Gorilla Clear Grip, but any glue that adheres to both PLA and TPU should work.

Check out my profile for other cap designs that fit the same TPU insert.