This reusable stopper will keep insects and sand outside your bottle, while keeping most of the drink inside. It works with opened bottlecap bottles - and can be printed in PLA!
Stoppers come off with a satysfying pop, while the loop saves them from getting lost in sand/grass.
You can print them in various colors to mark the bottles during a party/camping/barbecue.
changelog:
V1 - cover, isnt really watertight but prints well in PLA
V2 - stopper - springy inner stopper is intended for something like PETG or TPU, but even printed in PLA is almost watertight - few drops can escape if the bottle is turned over
V3 - stopper with sturdier connection to the loop. The loop and stopper are also a little easier to press-fit on bottle
no-loop version added
V3.1 - Minor cosmetic changes. The loop is even easier to press-fit on bottle