The fare for a standard one-way Trolley ticket is $2.50, and one-way tickets are good for two hours from the time of purchase. Kids below 6 ride for free with fare-paying rider; limit is 3. Transfers between trolley lines are free, provided it is to complete the one-way trip; but round-trips are not allowed on a one-way ticket. Transfers to MTS/NCTD buses, the Coaster and the Sprinter are also not allowed with a standard one-way Trolley ticket. However, a 24-Hour Pass (good for 24 hours from first boarding) is unlimited use, and allows unlimited travel on the San Diego Trolley system, as well as most MTS & NCTD bus systems, and the north country Sprinter light rail service for next 24 hours. A RegionPlus 24-Hour Pass allows unlimited service on all of the above named systems, as well as MTS Premium buses and the Coaster commuter rail, for 24 hours upon first boarding.