Welch Allyn 6v Halogen Lamp. This halogen headlight provides a focal source of illumination for diagnostic and surgical procedures. The iris diaphragm regulates the diameter from 3/4" to 6 1/2" at a distance of 14", and the open rib construction helps prevent excessive heat buildup. The adjustable plastic headband has a detachable connector and an on/off switch. Headlight comes with headband, wall transformer and mounting plate and operates at 110 to 130V, 50/60 Hz. Both headlight and transformer are UL listed and CSA certified.