A dumper or dumper truck or dump truck is a truck designed for carrying bulk material, often on building sites. A dumper has a body which tilts or opens at the back for unloading and is usually an open 4-wheeled vehicle with the load skip in front of the driver. The skip can tip to dump the load; this is where the name "dumper" comes from. They are normally diesel powered. A towing eye is fitted for secondary use as a site tractor. Dumpers with rubber tracks are used in special circumstances and provide a more even distribution of weight compared to tires. Continuous tracks allow the operator to carry heavier payload on slick, snowy, or muddy surfaces, and are popular in some countries. Rubber track dumpers offer even weight distribution for transporting heavy payloads over challenging terrains like mud or snow, popular in certain regions. Roll Off Dumpsters, contrastingly, are large, stationary containers designed for substantial waste management, easily loaded and transported by specialized trucks.