Of all can opener variations, the conventional top-cutter mechanism with all-metal construction and tight-fitting polymer handles are one of the more robust and effective designs. For comparison, Lagostina has a stainless steel can opener that uses hard plastic for its handles, turner, and lower gear bearing. The spacing of the gears as they mesh is also important. Too wide and the mechanism will jam on blunted metal; too narrow and risky manufacturing tolerances may increase the rate of defective units.
All-metal construction (including the turner and bearing), consistent quality (made in the USA) with polymer-insulated handles. Carbon steel blade and chromed steel frame. Conventional top-cutter mechanism (with precision-mating gears) works on all cans.
Conventional Top Cutter vs Side Seal Undresser
Universal top-cutting leaves rough edges, which is better than smooth-edge side-unsealing that produces metal slivers (better to get a small cut than to swallow sharp/thin metal shards).