The O-rings on an end piece are defective where do I get replacement?

On request we will send replacement. Please attach a photo of the end piece.

End piece ST1 requires 2 pie 5.5x1.5 or 5.0x1.5 FKM or NBR70

End piece ST2 requires 2 pie 5.5x1.5 or 5.0x1.5 + 1 pie 3.0x1.5 FKM or NBR70

End piece ST1-6mm requires 1 pie 3.1x1.6 or 3.0x1.5 FKM or NBR70

Adaptor cap AV 8 mm 1 pie 5.5x1.5 or 5.0x1.5 FKM or NBR70

Adaptor cap AV 6 mm 1 pie 3.1x1.6 or 3.0x1.5 FKM or NBR70