Is it active or passive? If it is passive it rules. Still cool nonetheless.

They offered one of each - the Magnum I was passive and the Magnum II was active.
For obvious reasons, the Magnum I is the one that's in demand today.
I've got a Magnum II - got a good deal on Ebay - but it's still good. It was retrofitted with a passive bridge pickup so you can have the best of both worlds.

Mine is a Magnum III, which is passive. They also have Magnum IVs, which are active.

From what I was told the older plastic backed models were made from the same plastics that were used to make propeller blades for helicopters.