You will always have an extra 9V Battery charged and ready to go when you have the Battery Recharger Kit.  While you are using one battery the other can be charging and ready to go when you need it.  Save money by not having to buying replacement batteries all the time.

Recharger Kit comes with a 9V Charger that plugs into your wall outlet and (2) Rechargeable 9V Nickel Cadmium Batteries.

This is a more economical way to purchases batteries---buying the Kit saves money and time. 

NOTE:

The Rechargable 9V Batteries can be used with any of your TENS, EMS or units that requires a 9V Battery.