A drop in golf cup hole for putting greens. I designed it for the StarPro greens but it should work for any putting green that is at least 9 mm thick.

There is a small internal fillet to help remove made putts with the putter or foot. I'm sure that the geometry is not correct to give proper lip outs, but we should roughly know when we hit a put that will lip out. Same goes for puts that are hit too hard.