The L-500 magnetic electric guitar pickup was released by Lawrence Sound Research (LSR) in 1979. Inheritor to the L-90XL throne, the L-500 was the next stage in the evolution of the ultimate guitar pickup by Bill Lawrence(Willi Lorenz Stich). Initially available as Lead/bridge (L-500L) with 9.6 Henry and Rhythm/neck (L-500R) with 4.8 Henry.
(pictured right: a post 1981 pre 1984 L-500L. This example was made before the switch to flat blades but after the addition of the bottom imprint. Early 1983 then?)