Here is a summary of the features and specifications of 4 Invacare Oxygen Conserver Tanks.
The smallest conservation tank available for the Homefill system can hold up to 57 liters of oxygen! It delivers up to 2 LPM (liters per minute) of pulse dose oxygen, and is perfect for those who need only this amount, for up to 24 minutes at a time.
It also only takes 24 minutes to refill. That means you can fill it up, go outside and work in the garden, or take a trip to the store, and be back in time to refill it for a second dose. It's also the most lightweight, smallest and most unobtrusive of the Homefill conservation tanks, weighing just 2 lbs. It measures 3 inches in diameter and 8.25 inches tall. The bag it comes with makes it easy to strap it on while you're using it, and going about your day.