A pair of BORG tubeless valves for road, CX/gravel or MTB. The base is round rubber. The collar is colour matched and there is an o ring to stop you scratching your rim.
The valves all have removable presta cores.
Do them up tight and you will get a good seal. Always tap the valve in place with a rubber mallet to ensure its seated before tightening the collar up. Install the tyre with soapy water and inflate. There should be no leak at the valve. If there is you have a year in the base tape or you have not fitted the valve correctly.
This is how you avoid installation woes.
Theses lovely valves are not carded to reduce waste.
40mm silver brass