(i) post and keep posted on the dispensing device from which such motor fuel is sold or offered for sale a sign or placard, at least twelve inches in height and at least twelve inches in width, stating clearly and legibly with the whole cent numerals at least nine inches in height and at least two inches in width, the selling price per gallon of such motor fuel; or

(ii) where such individual pump or dispensing device dispenses more than two differently priced grades of motor fuel, only the highest and lowest selling price per gallon of such motor fuel dispensed therefrom must be posted thereon in conformance with all other provisions of this subdivision; or

(iii) where a multiple product dispensing device is capable of dispensing multiple products at multiple prices, then the selling price per gallon may be posted thereon with numerals at least one-half that height and one-half that width required by subparagraph (i) of this paragraph, although numerals representing tenths of a cent may be displayed at no less than one-half those dimensions which disclose the selling price per gallon of such motor fuel dispensed therefrom. The signs and selling prices shall be posted so as to be clearly visible to the driver of an approaching motor vehicle or motorboat. The name, trade name, brand, mark or symbol, and grade of quality classification, if any of such motor fuel shall be permanently imprinted on said motor fuel dispensing device. The provisions of this subdivision shall not apply to a city, county, town or village which has already enacted and continues in effect a local law, ordinance, rule or regulation in substantial conformity with this subdivision. The provisions of this subdivision shall be enforced in the counties outside the city of New York by the county or city director of weights and measures, as the case may be, and in the city of New York by the department of consumer affairs. b. Any person who shall violate the provisions of this subdivision shall be liable to a civil penalty of not more than one hundred dollars and for any subsequent violation shall be liable to a civil penalty of not more than five hundred dollars. 6. Gasoline stations; air pumps required. a. Definition. As used in this subdivision: "dealer" shall mean any person owning or operating a premise or facility with four or more gas dispensing nozzles for the retail sale of motor fuels for use in motor vehicles. b. Any dealer must provide on the premises where motor fuel is sold at retail for use in motor vehicles a functioning motor driven air compressor capable of inflating automobile tires for use by customers during hours in which such station is open for business. c. Wilful failure to comply with the provisions of this subdivision shall subject a dealer to a civil penalty of up to twenty-five dollars for each day such failure occurs. If the failure to comply results from the breakdown of the air compressor, the failure to repair within a reasonable time shall constitute wilful conduct.