Dear Customer,
Here are the Orings in the enhanced multi-link 16mm fittings.
If you have any questions, feel free to contact us.
Inner O-ring BP-ML16-O10-BK
https://shop.bitspower.com/index.php?route=product/product&path=59_128_138&product_id=363
Inner O-ring Tool BPTA-ORFT16 helps to put the inner O-ring into the fitting much easier.
https://shop.bitspower.com/index.php?route=product/product&path=59_128_138&product_id=7971
Thread Oring BP-WTP-O10-BK
https://shop.bitspower.com/index.php?route=product/product&path=59_128_374&product_id=404