Maryland Code, Commercial Law § 14-702

(a) This subtitle does not apply to a secondhand watch which has been sold previously to a consumer and is returned to the seller within 30 calendar days for a refund, credit, or exchange in an amount equal to the full amount of the purchase price, if the seller keeps a written record which sets forth:

(b) The seller shall keep the record on file for at least three years from the date of the sale of the watch. The file shall be open for inspection during all business hours by the State's Attorney of the county in which the seller engages in business.