Novritsch Suppresor

I see no reason why it wouldn't work for any airsoft sniper if it does indeed work at all (provided said sniper has threading for an adapter at the end of the barrel of course).There is a demo video below the product description in the link you left. However, if you want to be absolutely certain, just wait until you see someone on the field with one and ask them about it to see for your self. For all we know the sound in the video could have been edited, tampered with or just a one off. Knowing novristch and the sly salesman he is, I wouldn't completely trust the video.
But the explanation for the way the suppressor works seems to be sound.
On a personal note, as much as I would enjoy having an even quieter gun, that's a lot of extra barrel length, and think it would simply get in the way too much tbh. I get by well enough with how it is atm.

I have suppresor, lenght is 12cm and sound difference is enormous. Without it it sound like .22cal (vsr-gspec), with suppresor its almost soundless on 20-30m. So, this suppresor works, but I think it's well overpriced.

It's far from optimal, but a decent design taking production quality (BB path alignment) and production cost into consideration.