It has to be like Stok? Stok isn't very good in my opinion and 6 hours to brew is too short. Even the 10 hours Stok's claims to brew is too short. Just buy a mason jar, pour grounds in and fill with water. Let it sit in the fridge for at least 18 hours. Buy an extra fine reusable filter and use that to filter out the grounds.

Here's what I use:

https://www.amazon.com/gp/product/B01JN2K046/ref=oh_aui_detailpage_o03_s00?ie=UTF8&psc=1

I use these grounds and love it:

https://www.amazon.com/gp/product/B01HFK955I/ref=oh_aui_detailpage_o03_s00?ie=UTF8&th=1