Need to move a heavy load around a warehouse? Forget the forklift: a robot will do your bidding.

Say hello to Freight 500, pictured, and its beefier sibling, Freight 1500. These are the latest machines to emerge from the labs of Fetch Robotics. Led by chief executive Melonee Wise, who was one of our 35 Innovators Under 35 in 2015, Fetch has been developing affordable warehouse robots for a few years now. Both robots are much larger versions of a small, rolling device called Freight, which was designed to follow warehouse workers as they picked products from shelves.

The robots are designed to replace trolleys and forklifts in warehouses. As their names suggest, they carry 500 or 1,500 kilograms, respectively, with the larger one designed to carry the kinds of loads you might usually see arriving at a warehouse on top of a pallet. Once loaded, they find their way around and avoid hazards using a combination of lidar and stereo cameras, running for up to nine hours on a charge and rejuicing to 90 percent capacity in an hour.

The robots join similar devices on the market made by the likes of Clearpath Robotics. And for now, in the warehouses of e-tailers like Amazon or online grocery retailer Ocado, they will continue to coexist with humans. That’s because while it’s easy enough for a robot to lift a large box, they currently lack the fine motor skills and versatility required to reliably pick up, say, a pack of batteries followed by a bottle of detergent.

But you can expect that to change. Fetch itself has already designed robotic pickers, a German firm called Magazino has a machine that can gather items from multiple different shelves, and Ocado has built robot grippers that can handle your vegetables. It’s just a matter of time before they start replacing humans inside warehouses.

(Read more: “35 Innovators Under 35: Affordable Robots for the Warehouse and Beyond,” “Inside Amazon,” “A Warehouse Worker’s Best Friend—or Replacement?”)