Your Lifefactory Baby Bottle is there for the whole adventure, so Lifefactory offers nipples that fit the 4 oz and 9 oz Baby Bottles in four sizes: Stage 1, 0-3 months; Stage 2, 3-6 months; Stage 3, 6+ months; and Y-cut nipples for the fastest flow of milk, formula, or other fluids. Made of silicone, BPS/BPA/phthalate free, and featuring a vented design, these nipples are made to take everyday adventures in stride. Features (2) Vented Silicone Nipples, 0-3 months (slowest flow) Use with Lifefactory 4 oz and 9 oz glass baby bottles BPA-free. Tested to meet FDA standards. Made in France Dishwasher safe (place on top rack)