Matching 1-way check valve to enema tubing size

Hello,

I was looking into purchasing extra matching check valves for this interesting higginson enema pump nozzle.

https://www.ebay.ca/itm/296309982259

Furthermore, the check valve I'm trying to find correct size to order is from this listing:

https://www.ebay.ca/itm/403604442729

I know normally nozzles are around maybe 3/8 inch and this listing is millimeter. Would it be better to first order the nozzle and once received I can then measure and order the check valve afterwards? Has anyone bought this nozzle with the ball tip?

Thanks

Buy a few different ones ..... the damn things are cheap. I'm sure it won't break the bank.

And take it from there ......

Another source for raw materials and parts is McMaster-Carr:

https://www.mcmaster.com/

They have latex tubing in various sizes, as well as connectors and check valves:

https://www.mcmaster.com/products/check-valves/check-valves-with-barbed-fittings-9/?s=ball+check+valves

Scroll down to find "Barbed Male Inlet × Barbed Male Outlet".