Name for a piece of climbing equipment produced by Black Diamond. The alien is a very small camming device(SLCD). Most camming devices require you to find a finger sized crack in the rock. The smallest aliens (there are about four sizes of them I think) can fit into fingertip sized cracks and in paticular they can fit into holes left in the rock when old pitons are removed (these are called piton scars).

Aliens cost about $70 a piece. I have used them within the last 6 months and they are brilliant. Black Diamond makes fantastic equipment and placing any piece of gear made by them gives you a little extra confidence on your climb