One of the many keys to placing a proper cam placement is making sure there is enough surface contact on all four lobes of the cam against the rock surface. Spring loaded camming devices are complex pieces of equipment. A basic understanding of how cams work is critical to finding safe, reliable placements. How cams work When you fall on a camming unit, three basic factors decide whether it will hold or pull out: how well the cams grip the walls of the placement (friction), how hard the cams push out against the walls of the placement (outward force), and how well the rock on the walls of the placement hold up to the pressure exerted by the cams (rock strength). Now, retract the cam lobes, place the head of the cam into the placement, align the stem of the unit in the expected direction of the potential load, and release the trigger. Verify that you have chosen the best size by making sure that the green Range Finder dots are lined up where the cam lobes touch the walls of the placement. Yellow dot alignment is okay too, but you must exercise more caution with the placement, because the cam will be less stable, hence more prone to walking, and it will have less expansion range left to accommodate walking to a wider position. If the cam you choose aligns in the yellow zone, the next larger size will align perfectly in the green zone. Use that cam instead, if it’s still on your rack. Never use a placement in the red zone unless it’s the only placement available. Four essential aspects to placing a solid and safe cam placement. 1. Amount of contact between the cam and rock surface, 2. Quality of rock or surface, 3. Quality of lobe placement, 4. Direction of pull.