D2 blade steel. Copper handle. Precision function. The Natrix is based on brother brand Zero Tolerance's 0770, which itself was inspired by the award-winning ZT 0777. This one offers upgraded D2 blade steel with a stonewashed finish that goes perfectly with the intriguing copper handles. (Yes, copper.) Since copper is denser than steel, this smaller knife has some heft--and a lot of style. You'll especially like the look once the handles have earned some patina.