The box is 35 mm square and 97 mm long. The valve was secured within the carton by means of an inner sleeve that locked together and a further lock-in card strip that formed the end of the box. Like many American valves of the Octal period the inner card was fixed to the outer sleeve by a stout metal staple. The only way to extract the valve is to damage the carton and thus prove that the valve has been opened.
 
 
 
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