These are bitspower enhanced fittings OD 16MM.
I bought these and ended up not using them. These are open box, I have used them for 1 day and put back.
All O rings are in great condition.
Link to store page: https://usa.bitspower.com/shop/index.php?route=product/product&path=482_541_545&product_id=7518
Selling these out since no longer needed.