The PB-4 is a pet care automaton — a small wheeled unit the size of a footstool that feeds, waters, and monitors domestic animals when owners are away. It dispenses food on schedule from internal reservoirs, maintains water bowls via a pump connection, and monitors animal vital signs through a passive biometric scanner. If the animal shows signs of distress, injury, or illness, the PB-4 alerts the owner and, if no response is received within thirty minutes, contacts an emergency veterinary service.

The PB-4 was designed for the substantial population of GLMZ workers who keep pets but work twelve-hour shifts in corporate facilities with no-pet policies. The unit cannot walk a dog, play with a cat, or provide companionship — it feeds, waters, and monitors. It is the bare minimum of automated animal care, and Meridian Domestic does not pretend otherwise. The marketing is refreshingly honest: 'Your pet won't starve while you're at work.'

The PB-4's biometric scanner has proven unexpectedly useful beyond its intended purpose. Veterinary researchers have used aggregated PB-4 data (anonymized, Meridian Domestic claims) to track disease patterns in the urban animal population. Two outbreaks of canine respiratory virus were identified weeks earlier than they would have been through traditional veterinary reporting, because PB-4 units across the city simultaneously flagged elevated breathing rates in dogs within specific neighborhoods.