The Black Diamond C4 Camalots' design increases their already enormous expansion range and weighs thirty percent less than the original. Black Diamond managed gave the C4 a broad range so that a couple half sizes became unnecessary. These updated cams even received the Best In Gear award from Rock and Ice. The C4s include a thumb loop that makes them about a billion times easier to place one handed, and gives you a second point to clip in to. Almost forgot, the C4's cost about the same as their predecessors