Wholesale Grav Labs Sip Series 4" Bubbler - Milk Carton Anything missing from your life? Try looking to the GRAV Milk Carton bubbler, a fully functional water pipe that should remind you of simpler times in the cafeteria. The open body allows for plenty of diffusion, while the narrow opening at the spout of the carton prevents splashback. Part of this complete breakfast. Features Part of the new GRAV sip series Stands 4" tall 14mm female joint Comes with a 14mm cup bowl Features a fixed fission downstem