This is a simple part meant to replace the little plastic bumpers that the backs of those classic brown church-basement-style folding chairs are supposed to rest on, after they break off or are otherwise lost. Recommended export chord tolerance is 0.02mm or less; solvespace 3.1 generates a very slightly broken STL at that level of precision as of this writing, but today's sophisticated slicers seem to be able to smile tolerantly at you and generate reasonable G-code anyway. Your mileage may vary.