This is an extremely rare Fender Custom Shop 51' Nocaster Relic Tele bridge pickup (that was a mouthful)!
These were made to duplicate the most powerful Tele (Broadcaster & Nocaster) bridge pickups Fender made in the very early 1950's (50-51 only).
It measures 9.8k ohms in the guitar! And has a wonderful smooth powerful tone....not the usual ice-pick when turned up.
You can distinguish these pickups by the Custom Shop dull/dark Relic alnico 3 pole pieces (no other Tele p/u has), w/ the black & yellow cloth covered wires, 'tin' under plate, & the Custom Shop sticker on the bottom.