Cams, which are also referred to as Spring Loaded Camming Devices (SLCDs) or friends, are used to attach a climber to a rockface. To use an SCLD you simply pull a trigger, which causes the cams to move together, before inserting it into a crack. When you release the trigger the cams expand locking the SLCD in place. I'm sure you get the picture. It's really quite simple. At Banana Fingers, we stock cams in a variety of different sizes to fit a wide range of cracks.