TELESIN Accessories for Xiaomi Yi Standard Frame Housing + Mount Base + Screw Protective Hard Case For Xiaomi YI 4K Sports Action Camera 2

While flimsier than expected (the frame is made of quite flexible plastic), funcionality wise, this is great. Fitting the camera into it is trickier than it could be, I expect the plastic will crack over time (after which I'd probably use this as a template to design something better with 3d printing), but it does work. Because of the materials, the frame is extremely light, which is a nice bonus if you happen to be using it to mount it to something you don't want to increase the weight/modify the balance of. Could do with a bit more space around the USB port, it's a bit awkward to fit a cable in while the camera is inserted, but otherwise I have no complaints.

Perfect for when you want to use 'gopro' style mounts. Bought this so that I could mount the camera on existing mounts where I didn't want / need to use the waterproof housing, does a great job.

Great mount/case for yi 4k