You have the closed bolt...you need the NPAS unit that's sold attached to the rod. You'll have to take it apart and swap it onto your bolt.
You cannot simply buy the Open bolt nozzle and expect to drop it into your gun. There is a full WE open bolt conversion kit (chamber, barrel, bolt, etc...)...and then you can swap in an NPAS float valve, or swap to the NPAS open bolt nozzle.
If you do the open bolt conversion...you'll need to convert your mags too.
Is it worth it?
1. WE is switching/making everything open bolt now
2. Gas efficiency is better
3. Accuracy out of the box is better
Lots of guys still run the closed bolt system...'cause it's what they bought.
Up to you