MTIs brightest exam light uses 7 LEDs and has a slightly larger 3-1/2" light head, providing maximum illumination and operational ease. Can be used with either a caster base or floor stand. 2-year limited warranty.Physical dimensions: head diameter: 3-1/2"; caster base height: 73-1/2"; floor stand height: 71-1/2"; caster base diameter: 23-3/4", floor stand diameter: 15".