Complete with 1.5 meter ss rod optical bench having the following components L.B. Photometer Head : made from precision optics. Light Form two sources fall on either side of a uniform white opaque screen and is reflected by side reflectors. Then it passes through LB cube. Observing the field through a telescope, tow light intensities are compared directly.Lamp House : tow lamp houses with electric bulbs workable on 220v.