RTD is the transit system for Denver Colorado. RTD Subcontracts out about 55% of their service to two Subcontractors, First Transit and Laidlaw. RTD supplies them with hand-me-down buses, which were previously used by RTD. They are marked with a suffix on the end of the fleet number representing the assigned Subcontractor. First Transit buses have an "F" as the suffix, and Laidlaw buses are marked with "L". RTD buses have no suffix at all.