You'll find that the 1/8" hole is plenty to dig the beak of your pick into; however, the placement is shallow. This size of of holes trains you to maintain pressure on the hole though it is forgiving when you maintain consistent tool pressure through the move. This size hole is slightly easier than a 60-degree dimple.
This is a great way to teach the intermediate climber accurate tool placement.
The bridge is attached perpendicular to the backplate.
Size: 3 x 1/8" holes
Stands off the wall: 15/16"
Backplate: 3" x 5" Oval
Bridge Orientation: 0 degrees/Perpendicular to the back plate
Material: Stainless steel
Hardness Comparison: View Chart and Descriptions
RESPONSIBILITY: Please be aware that it is unacceptable to drytool at your local crag. Drytooling damages natural rock. You should drytool only in places where the local community has dedicated the area and never on established rock climbing routes.
DRY TOOLING ETHICS: What You Should Know before heading out.