we son be a slender baby even though he be 13lb at 2 month old . we be use cloth diaper and be unsatisfied with the loose fit of the regular Bummis cover over we Kissaluv Contoured diaper . someone recommend that we try use Bummis Swimmis as diaper cover because they have a much trimmer fit . -lrb- the manufacturer do say be okay so long as the cover you use for diaper be never use as swim diaper . -rrb- now , with the swimmi and the contoured diaper we have get a fit that be as trim as a disposable diaper and much cuter !