Hybrid diapers are designed to combine the benefits of cloth with the ease of disposables. They consist of a waterproof outer cover and two inner absorbent-layer options: a cloth insert or a disposable insert. Cloth inserts are basically rectangular runners, made in a variety of fabrics including cotton, microfiber, and/or hemp. They're sometimes filled with an ultra-absorbent microfiber. Disposable inserts are the single-use version; you can buy rolls of 100 inserts for roughly $5. The idea is that like disposables, they're convenient when you're on the go, but they generate less waste than their full-size cousins. They're usually low on chemicals, and some are even biodegradable. You can reuse the covers with hybrids too.