The OSI is the single edged version of our OSS. Hollow ground to a thin, ultra keen edge it's an awesome "sticker" and will cut and slash with the best of them. Extensively field tested by our President, Lynn C. Thompson, in Australia in 2007-08, it has field dressed, skinned, and "broken up" dozens and dozens of animals from wild boar to buffalo and proved to be outstandingly efficient field knife. It's also ideal for use in countries or localities that prohibit or restrict double edged knives.