#3 has a 75 degree incut. It's rounded so you can rotate it to make it easier and harder.
3/8-16 Zinc Round Base T-nuts
#9 is a half inch edge, flat and requires body tension as the wall gets steeper. Sold as a set of 2.
Set of 2 System Feet.
#4 has a rounded top with little incut. The bottom side has a 115 degree slope to it which is considerably harder to stand on. Sold as a set of 2.
