As noted on the side, each of these cartons holds a dozen identical cards with one particular toy. It also states the full item number for the card in question.
9 1/4 in
6 3/8 in
4 1/8 in
note: an eBay seller in Canada told me of re-used shipping boxes holding 48 cards each: they had been turned inside out and re-taped, so the original printing was on the inside. This printing included Playskool (a Hasbro brand which Triang also marketed outside the US) and Triang-Meccano (used for model trains) with "Toronto, Ontario" now on the inside, and a Spacex model name with the number 48 marked on the outside.