David Round RailRunner Tractor Drives can handle loads from 1,000 to 30,000 pounds with travel speeds reaching up to 300 feet per minute. Featuring four universal flanged trolley wheels and a spring-loaded rubber drive wheel for added stability. Compatible with tapered and flat-flange beam styles, as well as heavy-duty chain/sprocket drive systems. Powered by a 240/360V - 60Hz 30-phase system, manufactured in the USA with most items available for immediate shipment from stock. Customization options include various track widths to accommodate travel speed and space constraints. Additionally, Explosion Proof (EX) rating, enclosed track, free-wheeling, and stainless steel construction are also available upon request. Please contact us for further details regarding customization. FOB Shipping Point applies with the possibility of additional steel surcharges.