Try this Joovy Boob glass bottle with silicone sleeve. It is 5 ounces. This is one of the best performing bottles with fewer parts to clean and the only internal quad vent on the market. The nipple involves a wide natural latch that won't collapse. Comes with bottle, nipple, ring, and yellow silicone sleeve. Helps when going from breast to bottle to breast and back again. best bottle breast feeding boob joovy glass silicone sleeve