THE PURPOSE OF THE PECKER IS TO TUNE YOUR RADIO OR AMP WITHOUT PUTTING IT IN A LOCK KEY MODE. ALSO YOU ARE TUNING THE AMP IN THE SSB MODE. IF YOUR AMP HAS A LOW /HIGH VOLTAGE SETTING, ALWAYS USE THE HIGH VOLTAGE. YOU WILL DRAW MORE GRID CURRENT IF YOU USE THE LOW VOLTAGE SETTING. THE OUTPUT OF THE PECKER OPERATES AT APPROX. 33% DUTY CYCLE. TUNING YOUR AMP WITH THE PECKER WILL EXTEND THE LIFE OF YOUR TUBE OR TUBES. This unit is designed for 8-pin ICOM rigs. It has been tested, but very lightly used since I got rid of my amp shortly after buying this unit, and in perfect, like new condition. It requires a standard 9-Volt battery for operation, and lasts a long time. Price is $49 shipped and insured. Smoke free home. Contact me with questions or to purchase through PayPal (preferred) at my address: ak3q (at) ak3q.com Sorry, no International orders. No returns due to parts swappers/scammers, but I only sell what I would buy myself. Thanks for viewing!