Paragraph 4
Subject to the provisions of this paragraph, in any proceedings (whether in England or Wales or Scotland) for an offence under the principal section it shall be a defence for the accused to prove—
that he purchased the helmet in question as being of a type which under the principal section could be lawfully sold or offered for sale, and with a written warranty to that effect, and
that he had no reason to believe at the time of the commission of the alleged offence that it was not of such a type, and
that it was then in the same state as when he purchased it.
A warranty shall only be a defence in any such proceedings if—
the accused—
has, not later than three clear days before the date of the hearing, sent to the prosecutor a copy of the warranty with a notice stating that he intends to rely on it and specifying the name and address of the person from whom he received it, and
has also sent a like notice of his intention to that person, and
in the case of a warranty given by a person resident outside the United Kingdom, the accused proves that he had taken reasonable steps to ascertain, and did in fact believe in, the accuracy of the statement contained therein.
Where the accused is a servant of the person who purchased the helmet in question under a warranty, he shall be entitled to rely on the provisions of this paragraph in the same way as his employer would have been entitled to do if he had been the accused.
The person by whom the warranty is alleged to have been given shall be entitled to appear at the hearing and to give evidence, and the court may, if it thinks fit, adjourn the hearing to enable him to do so.