Bottle is sturdy and sanitary, made of FDA compliant, food-grade polyethylene plastic that is durable yet translucent enough so you can see the content level. Nipple is made with a special rubber formula to prolong nipple life and improve pliability. Threaded top for a secure fit. Bottle is 4.25 inch square by 10 inch high, holds 2 quarts. Nipple is 1 inch diameter by 3 inch long.