On April 2nd I received an email from CNOC Outdoors saying that they were now offering tethered replacement caps for pre-2019 Vectos. 2 dollars and 6 days later I’m pleased to announce that my replacement has arrived.
In addition to the tether you’ll note that the threads appear to be much deeper and that the ribbed closure on the outside of the cap is also deeper and more widely spaced.
The new cap weighs 4g whereas the old cap is 2g.
Don’t know how much more there is to say about a cap, honestly.