Rechargeable extinguishers can be refilled so that, rather than throwing them away after use, you can get them refilled. However, it depends on your local recharge sources as to whether this is actually cheaper enough than buying a new one. Check with your local fire department and/or search online for recharge companies near you and verify that they will recharge this specific unit and what they would charge to do so.
This fire extinguisher is rechargable. Meaning that if you shoot it off it can be refilled by a qualified service company. However this particular brand costs more to recharge than to just buy a new unit. I would personally recommend buying a better quality brand (Badger, Ansul, or Buckeye) than this.
*Source - I work for a company that services fire extinguishers.