You'll appreciate the versatility of the Tweedle Bugs diaper covers! They fit nicely over all types of cloth diapers including fitted diapers and prefolds. The soft extra leg gussets contour around the baby's legs making it fit any body shape. This helps prevent leaks! Tweedle Bugs diaper covers are made with sandwiched PUL(soft knit inside and out) and high quality hook and loop or snap fasteners for a custom and secure fit.  The "laundry safe fold back tabs" are designed to keep the closure securely in place and not on your other items. You'll welcome the non-wicking soft laminated knit polyester fabric for ease of use and laundering. The superior PUL waterproofing will keep you and your baby's clothes dry while it provides a breathable environment promoting healthy skin. Sizes are Newborn 6-11lbs, Small 9-15lbs, Medium 14-26lbs, Large 25-40lbs.