I was not familiar with these - what a great concept. Reading reviews it looks like the green painted version fails often (corrodes and locks to threads). Same company makes a brass version for more money that gets very good reviews:

https://www.amazon.com/Flow-Security-Systems-Construction-Conservation/dp/B00G4NI0RW/ref=sr_1_3?dchild=1&keywords=Flow+Security+Systems&qid=1600790197&sr=8-3