GRAV® Milk CartonGRAV Milk Carton Bubbler Nostalgic Design & Modern Aeration Take a trip down memory lane without sacrificing high end performance with the GRAV Milk Carton Bubbler. A centerpiece of the celebrated GRAV Sip Series, this functional masterpiece reimagines the classic school lunch silhouette into a high performance water pipe. Standing at a compact 4 inches tall, the Milk Carton offers a surprisingly large internal volume, allowing for deep, satisfying