From left to right on 2nd image;

1: Round Top

2: Flat Top

3-5: O-Ring Sealing, Plus Cutaways, SAE AS 010 and Metric 2x6mm O-Ring Sized Versions

6: TPU Printable O-Ring Insert for SAE and Metric Sized Caps (Insert so 45 degree angle faces out)

7: Manufactured Cap for Reference

All files are oriented for optimal printing, Caps use between .75-1g of filament each.

Print Settings:

Recommend to print in PTEG as PLA isn't as outdoor resistant. .6mm nozzle, .2mm layer height. Should print fine with a .4mm nozzle.