The ABS Vario is no longer available in the 40-liter size. At this time, you can purchase the Vario in these sizes: 8L, 18L, 24L, 32L, 45+5L. You can buy the base unit and the Vario 32 zip-on or the Vario 45+5 zip-on pack to go along with the base unit. To compare other avalanche air bags that were tested, check out the Best Airbag Avalanche Pack review.
We like the ABS system because instead of using one 150L bag like most airbag packs we tested, it uses two airbags totaling 170L. This offers some redundancy and greater "buoyancy." We also love that you can zip different packs onto the same base unit so once you own the base unit, it is "only" another $100-$200 for each new "pack." If you don't like the Vario pack zip-on designs, there are many other packs from a wide range of manufacturers that offer zip-on options, including those from Mystery Ranch, Da Kine (DaKine Altitude ABS is a favorite among OGL friends) and Arva. ABS and packs using ABS technology are the only ones using compressed nitrogen instead of compressed air. Nitrogen is better performing in colder temperatures and allows you to use a smaller canister, but it is more difficult to travel with and more costly to refill. The other disadvantage was the price; at nearly $1300 for a full unit it is one of the most expensive airbag packs in our review.