Specifications include, but are not limited to: Powertrain: Engine: Appropriate engine size for size of bus. Engine block heater Fast idle feature GVWR: minimum 25,999 lbs. Fuel Tank: minimum 60 gal. with locking cap Transmission: Allison automatic or approved equal Axle gear ratio: type and capacity as recommended by manufacturer for vehicle as equipped Rear air suspension Brakes: hydraulic, 4-wheel ABS Wheels: dual rear, single front Tires: steel-belted radial size and load range recommended by manufacturer for vehicle as equipped Dual batteries Cruise control Tilt steering column Interior: Thirty-six (36) to Forty-four (44) passenger body design All seats high-back design with recliners and matching upholstery, level 5 preferred Retractable lap and shoulder seatbelts for all seats Aisle side seat sliders for all double seats Interior LED lights