The WM-5 is a load-carrying domestic automaton — a squat four-legged platform the size of a large dog with a flat cargo surface on its back, designed to follow its owner and carry shopping, supplies, and personal items. It can haul up to 80 kilograms across any urban terrain, navigate stairs, squeeze through market crowds, and return to a designated home address autonomously if separated from its owner. It is, essentially, a mechanical pack mule for the consumer market.

The Porter is Hearthstone's answer to a simple problem: people in GLMZ buy things, and carrying those things home is inconvenient. The unit follows its owner using a short-range tracking beacon worn as a bracelet or clipped to a belt, maintaining a two-meter following distance and adjusting speed to match the owner's pace. It has no personality, no voice, no interaction capability beyond a single status light that turns red when overloaded. It carries things. It follows you. That is all.

The WM-5 has become an unofficial fixture of GLMZ's market districts, where hundreds of them trail behind shoppers like mechanical ducklings. Vendors have adapted to their presence, designing stall layouts with Porter-width aisles and low counters that allow the units to receive items directly. The secondary economy of Porter accessories — weather covers, anti-theft locks, custom paint jobs — generates more revenue annually than the units themselves.