[5] The first prototype was created in 1959, and the lamp was commercialized in 1960 by the Tensor Corporation.

The first Tensor lamp consisted of a 12-volt automobile parking light bulb and a reflector made from a kitchen measuring cup.

Monroe fixed the cup to a metal tube that was attached to a transformer, which reduced 115-volt house current to 12 volts.

Because of the small bulb, the entire lamp could be made smaller with a light-directing shade.

[1] Its main competitors during the 1960s were the similar-looking Lampette brand of lamps manufactured by Koch Creations,[1][7] the Mobilette,[1] a series of Italian designed lamps sold by Stiffel,[1] and Lytegem lamp designed by Michael Lax and manufactured by Lightolier.