Are twinsets heavy?

It’s understandable that people always think of twinsets as big and heavy, but this is not the case with twin 7’s.
The Faber website lists the weights of all their cylinders:

Single 12L cylinder: Single 15L cylinder: 12L plus pony: 15L plus pony: Twin 7L cylinders:

12-15kg 16-18kg 16-19kg 20-22kg 15kg

As you can see, twin 7’s are lighter than a 15L, and about the same as a heavy 12L. And compared to a diver with a pony, there’s no comparison. If you want to be redundant, a twinset is by far the lightest way of doing it.

And, just for information:
Twin 10's weigh 22kg
Twin 12's weigh 32-40kg

So if you're a 15 + pony man, you might want to take a look at the fact that your setup weighs the same as twin 10s.