The first ~1500 Go Direct® pH Sensor (GDX-PH) units shipped in July 2017 with the pH electrode in bubble wrap. This means that the Go Direct® Electrode Amplifier (GDX-EA) is not attached to the pH electrode.
Before use, unwrap the pH electrode from the bubble wrap and attach the electrode amplifier to the electrode. Push the BNC connector of the electrode onto the connector on the electrode amplifier, then turn the BNC connector about one-half turn clockwise. Make sure it is secure.
You should store the electrode and the amplifier connected in this way. You do not need to separate them again or store the electrode in bubble wrap.