Bill Lawrence L500RB Humbucker Rhythm Pickup
From the package:
"The original L-500 Bill Lawrence humbucker sound quality combined with high performance. This pickup is capable of reproducing almost any guitar sound imaginable: Fully shielded, high output, 4-conductor for multisound wiring. Complete with all mounting hardware. With careful use of volume and tone controls, these pickups make obsolete the need for a complete collection of other brands of "specialized" pickup."