Size and handle material. CA52161 is the smaller knife: 3.5 inches closed with a 2.5 inch black stonewash drop point blade and a black G10 handle. CA52116 is larger at 4.5 inches closed with a 3.5 inch satin-finish blade and a nylon handle. Both are stainless linerlocks.
A full inch of blade separates them. CA52161 at 2.5 inches is a genuinely pocketable everyday knife. CA52116 at 3.5 inches is a larger working folder that carries more visibly.
They also use different Case pattern numbers, T01193.5 and T0124.5 respectively.
CA52161 uses G10, which is harder, more textured and more grippy. CA52116 uses nylon, which is lighter and less expensive. Both carry an inlay shield, a thumb stud and a pocket clip; the larger one adds a thumb ridge.
Blade finish differs too: black stonewash on the small one, satin on the large one.
The smaller G10 version if you want something that disappears in a pocket with a grippier handle. The larger nylon version if you want more blade and less weight.
Both sit in our Licensed & Movie category and both are specified as stainless.
Specifications above come from the manufacturer. Live prices and availability are in the strip below, pulled from the catalog at build time rather than typed into the copy, so they cannot go stale on this page.