Features:
1. True Hi-Flow Design
2. Hi-Quality Brass Material.
3. High Durability Nickel Finished.
4. Design For Multi-Link Extension Application Via Acrylic Tube OD 16MM.
5. RoHS Compliant
Thread: G1/4"
Thread Length: 5MM
The extra Oring is for the tube which OD is a little smaller, such as brass tubing after cutting.