I bought a set of the T2013 (single coil in mini-hum shell) and I'd swear they are repackaged Surf 90's—or they use the same components. The pole magnets look identical, the black top material looks identical, with the same center hole and spacings, and they have the identical fake adjustment screws. the Carl Dearmond site claims they are 5.47 OHMs (wha?) but the ones I have in hand actually measure 7.7k which lines up with the GFS website spec of 7.8k in the neck.