The Opinel folding pocket knife is absolute beauty in simplicity. No fancy liner locks or thumb levers. Just a simple twist of the collar locks the blade in either the folded or extended position. The Opinel carbon steel blade is harder than the stainless steel version. That means it's easier to sharpen and will hold it's edge better. The downside to the carbon steel blade is that these will rust if used in damp environments. The cure for that is to oil your Opinel carbon steel pocket knife regularly. The Opinel No.7 Measures 7" fully extended and just under 4" closed.