#2 is a smear disk all the way around. It is very hard to stand on. Sold as a set of 2.
#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.
#5 is slightly harder to stand on than #4. It has a rounded top with barely an incut. Sold as a set of 2.
#6 is larger than #3, #4 and #5. It is excellent for a beginner or to use on a steep wall. Sold as a set of 2.
#7 is an oval cobble. It is barely sloping so you could almost call it flat on the wide side. It's a great intermediate to advanced hold in steep terrain. On the short side the angle is about 135 degrees sloping so on vertical, no problem. On a steep wall, the short side gets considerably hard to stand on. Sold as a set of 2.
#8 is a split cobble. It has a slight slope 105 degrees. There is a lot of landing surface. You can rotate it to the rounded side for a much more difficult to stand on hold. Sold as a set of 2.
#9 is a half inch edge, flat and requires body tension as the wall gets steeper. Sold as a set of 2.