I couldn't find a perfect case which holds my GoPro Hero Session, so thought to give it a try to AmazonBasics X-Small GoPro Case. The product which was delivered in original AmazonBasics package looked and felt good. The case is well build and doesn't feel cheap. The material is I think nylon and is water repellent. However I did not test by immersing it wholly in water but I am sure it will hold off light rains. The outer covering is quite sturdy. Inside the case is made of foam which is cut for the camera and its accessories. The good thing is that the product ships with the part of foam which is cut. I kept some of the foam and adjusted it for my Session. The top flap has a mesh with zip which is useful to keep chargers and other stuffs.
I am totally satisfied with the product as off now. However, might need something bigger when I have some more accessories, but right now it holds all my GoPro stuffs together (except the mini tripod, ofcourse).