OOK 50034 Ideal for concrete/brick and hardwall surfaces. Cannot penetrate concrete walls w/o drilling first. This last is based on 1 trial-by-error experience. Again, one person's experience: Nails will not bend, but they don't seem to be able to penetrate concrete without the help of a drill. Includes 1-Inch, 1-1/4-Inch, 1-1/2-Inch and 2-Inch nails Ideal for concrete/brick and hardwall surfaces. Cannot penetrate concrete walls w/o drilling first. This last is based on 1 trial-by-error experience. Includes 1-Inch, 1-1/4-Inch, 1-1/2-Inch and 2-Inch nails