Leak resistant travel cover. The silicone nipple is the same shape and feel as the GumDrop Pacifier, and the narrow bottle design is perfect for older infants to hold. GumDrop bottles feature a slim neck design and include a leak-resistant travel cap. Features a leak-resistant travel cover and 100% silicone nipple. Includes slow-flow nipple. One 4 ounce Slim Neck Bottle.