Screw-On Premium Pump Hose for High Pressure Wings, Kites, and SUP's.

Threaded end that attaches to the pump.  This is most often found in stand up paddleboard, kayak, and other high-pressure (12 to 20 PSI) pumps.  

Now used more and more among kite and wing brands such as Duotone, Naish, Flysurfer, F-One, CrazyFly, and others.  

If you have a pump that requires the thread-on attachment, but a kite, wing, or other inflatable that doesn't use the grey end in the photos, add this adapter to make it work on Cabrinha, Ocean Rodeo, PLKB, On, Slingshot, and others:  https://adventurekiteboarding.com/products/copy-of-wmfg-boston-valve-threaded-valve-adapter