That's slightly misleading, Gunnar. There are at least a half-dozen brands, all of which, on the consumer level, are the same size.
By the same token, loose gelatin powder is much more difficult to find, nowadays.
All of which is why most current recipes say X envelopes rather than X teaspoons.
Professional kitchens are more likely to use sheet gelatin, rather than powdered, anyway.
They have taken the oath of the brother in blood, in leavened bread and salt. Rudyard Kipling