I liked the bottles. Too bad the puppies did not. They didn't like the harder nipple tips! It took too many tries with scissors to get the cross-cut in the nipple tip to allow for a small, slow but steady drip. It would have worked perfectly had the nipples been made from something more flexible like silicone. My puppies were 3.5 to 4.4 ounces. These might work well for a little larger puppies with good suckling strength.