HOW DO I OPEN THE BATTERY COMPARTMENT?

This technique works for WonderFlex, NuFlex, and MiniFlex 2 models. You can also try wearing rubber gloves for improved grip. Please contact us if this technique does not work:

1) Open the battery compartment by pushing outwards with both thumbs on the compartment cover. 

2) If that doesn't work, nudge the battery cover open with a dime at the base of the u-shaped cover as shown below: