Hi everyone
I saw this video (see link below) from Stella where she was in this sort of bag that she had filled with gunge and I was wondering if anyone knows what it is or what it is called and most importantly where I can buy it.
In advance thanks.
https://stellas-store.umd.net/download_info/gak-sack

Looks like a Neoprene Sleepsack to me.

Cool thanks any idea where I could get it for a cheaper price?

Cheaper than what? The prices are clearly shown online and you can compare prices and quality.
Like with nearly anything, you can look for second hand option or maybe make your own if you have the skillset.

Well sorry that I asked

Love the video and concept. Definitely gonna have to give that a go!!