Welch Allyn GS 777 PanOptic Prestige Wall UnitA reliable diagnostic solution that delivers accurate results whilst providing energy efficiency and cost savings. Welch Allyn Green Series 777 Wall Transformer configured to your needs. Help reduce costs with a more energy efficient product than the 767 Wall Transformer Help improve workflow and save energy with handles that automatically turn on off Quickly and easily upgrade from the Welch Allyn 767 Wall Transformer to the Green Series 777 Wall