I used this on my SD2100 and modified F1A4 (I no longer have these detectors) and liked the modified version of the Minelab target signals and it did seem to give a better clearer signal with more sensitivity. It's in very good condition.
The following is from the instructions-:
Operating in M/LAB MODE:
First mode is the M/LAB MODE which is very similar to using your detector with out Super Fix except that it provides the added benefits-
(a) Super Fixs modified version of the original high/low or low/high target audio signal is now heard when operating in the M/LAB position.
(b) Features a soft start up feature which eliminates the loud bust of audio normally heard in the headphones at switch on.
(c) Provides an inbuilt speaker with separate On/Off switch.
(d) Ground noise is partially decreased enabling the detector to run smoother.
(e) Sensitivity to targets is increased.
Many more benefits were claimed for the Superfix mode, but it is like a totally different detector and I personally (as well as many others) didn't like it.
I think it's worth it for the benefits in Minelab mode though.
I'm asking $150 and will post (the speaker holes have been taped over) It originally sold for around $1100
The following is from the instructions-:
Operating in M/LAB MODE:
First mode is the M/LAB MODE which is very similar to using your detector with out Super Fix except that it provides the added benefits-
(a) Super Fixs modified version of the original high/low or low/high target audio signal is now heard when operating in the M/LAB position.
(b) Features a soft start up feature which eliminates the loud bust of audio normally heard in the headphones at switch on.
(c) Provides an inbuilt speaker with separate On/Off switch.
(d) Ground noise is partially decreased enabling the detector to run smoother.
(e) Sensitivity to targets is increased.
Many more benefits were claimed for the Superfix mode, but it is like a totally different detector and I personally (as well as many others) didn't like it.
I think it's worth it for the benefits in Minelab mode though.
I'm asking $150 and will post (the speaker holes have been taped over) It originally sold for around $1100