I bought the 121GW on Kickstarter in 2018.
It came with that nice pouch, and those great test tips from B.T.C.
One of the useful feature of this combo is, that it is possible to make quite stable mΩ measurements in its 50 Ohm range.
After 6 years of intense use, the red tip now showed unreliable Ohm measurements, as the shorted tips are reading unstable ~100..1000 mΩ, instead of < 100mΩ, as before.
This prevented a quick analysis of the power supply fault of my FLUKE 5442A calibrator, see here:
https://www.eevblog.com/forum/metrology/lowest-drift-lowest-noise-voltage-reference/msg5258283/#msg5258283I already wanted to discard the tips, but had a closer look, as the tip needle could somehow be rotated inside the rubber grips.
To my big joy, the grips can be pulled downwards, if you carefully grab the tips with a pliers at the thread.
The tip needles were tightly clamped to some cable clips, and the cable's wire, maybe silver plated copper, is clamped at the other side.
Latter seemed to be the problem, that due to oxidation this connection made bad contact.
So I used a 20W soldering iron with a bigger tip, and soldered the end of the wire to the clip.
Afterwards, the test tips are again showing stable 100mΩ when shorted.
Great quality, and I just love such repairable test tips. Very rare!
Frank