100ml Squeezable Bottle Dispensing Bottle with Luer Lock Transfer Cap 10 Units

None of the caps seal. Had to use a small o-ring at the base of the threads to seal caps.

None of the caps seal on any of the bottles. When you have a liquid in them (like DIY e-juice) and you go to fill your tank or other container, your bottle contents will leak out from under the cap when you invert the bottle and start to fill your secondary container (tank or whatever). To be clear, your liquid will come out of both your blunt needle tip AND from under the cap making quite a mess.