From where can one purchase a Spare Air tank?

You can purchase a Spare Air tank from a variety of online retailers, scuba diving equipment stores, and sporting goods stores. Some popular places to purchase a Spare Air tank include:

- Amazon

- eBay

- Walmart

- Dive shops and scuba diving equipment stores

- Sporting goods stores like REI and Cabela's

When purchasing a Spare Air tank, be sure to choose a reputable dealer and inspect the tank for any damage or defects. It's also important to ensure that the tank is compatible with your scuba diving equipment.