The Alembic Hot Rod Kit, introduced in 1973, was one of the first aftermarket pickup replacements. It was designed by Rick Turner to boost the output of Gibson pickups by swapping out the original Alnico magnets for stronger ceramic ones. The kit consisted of two ceramic magnets, wooden shims, copper tape, shielded black wire and instructions. These kits were used for pickups with under-the-pole magnets - including Gibson single coils and humbuckers, Guild humbuckers etc. They could also be used for Gibson mini-humbuckers if you (carefully) shortened the magnets.