Warning instructions:RISK OF PINCHING AND CRUSHING: CHILDREN MAY NOT USE THESE TOOLS. RISK OF FLOOR DAMAGE: USE SUITABLE FLOOR PROTECTION WHEN MOVING HEAVY OBJECTS.Heavy-duty: Max weight 500 kg (When using both movers)Movers: Rails made of iron, wheels made of plastic (pp), brake pad made of plastic.Length: 540 mm, extends to 800 mm Protective pads: On top of the rails that protect your furniture.Inner fit for your furniture: 440 mm to 696 mm (adjustable length)Outer measurements: 50 mm x 43 mm x 457 mm to 717 mm (adjustable length)Disclaimer: Variations of +-3 mm will occur on each item.Typical use: Use the brakes to prevent rails from moving, and lift what you want to move on top of the rails, unlock the brakes and move the item.