The EMG II Electromyography Amplifier is an internally powered high gain electromyography (EMG) unit which amplifies the extracellular potentials of muscles when an electrode needle is inserted into the muscle. The electric signals are detected by the tip of the electrode needle. The amplifier magnifies the electrical impulses and makes them audible through the unit's speaker or earphone.

The EMG II Electromyography Amplifier is powered by four AA (or R6) alkaline batteries (1.5 volt each). The amplifier circuit is designed to filter out common but extraneous noise such as that emitted by fluorescent lights.

A connection cable is provided with the amplifier. This cable is used to connect the reference electrodes and the electrode needle to the amplifier.

This device is classified as Internally Powered Equipment designed for operation at Safety Extra-low Voltage. It is specified as a Type BF device with Applied Part and Ordinary Equipment without protection against the ingress of water.

This device is specifically designed to facilitate the therapeutic injection of Botox®, a formulation of botulinum toxin type A derived from the bacterium Clostridium botulinum. Proper training is essential for the use of this device in the accurate identification of a muscle.

BOTOX® is a registered mark of Allergan.