This is a brand new 6-pack of  Basic Comfort  onesie garment extenders . The great thing about these extenders is that they come in 3 different size snaps in one package . They can add up to 6 more months of wear to the current onesie because they extend 3-4 more inches to the garment. The material is a soft sturdy poly /cotton which is machine washable. They fit most popular brands and off brands, but they may not fit some. There are too many brands to list on what works and what doesn't because of people's perception on what they think doesn't fit. Sometimes the spacing between the snaps may not exactly line up  but if you are putting clothes over the onesie it won't show anyway. Also sometimes the snaps are hard to snap on certain onesies but put a little extra pressure and it could work . 

I will gladly refund your money less the shipping costs if you are not happy with the item, please let me know.