I found these 2mm jacks the last time I was in Skycraft (their website doesn't show 1/10 of what they have in the store so don't let their website fool you). I was actually looking for banana plug jacks, but I thought these might be just the right size to connect to my multimeter leads and sure enough they were. I have since tried finding them on Jameco and Sparkfun, but have not had any luck. Unfortunately, I only bought 2 red and 2 black, so these are the only adapters I have made so far. Please note, there is a small nut on these that I did not insulate. Do NOT use these on high voltage circuits.
The other pieces are just 2 standard alligator clips with rubber insulating jackets and 2 mini-grabber connectors. The alligator clips I had to bend the wire stays out and solder the whole thing to the threads of the 2mm jack. For the mini-grabbers I had to drill holes in the back end of the spring base to have a place to mount the 2mm jack. When working with the grabbers, you may find it's easier to depress the spring button to extend the lead and unbend the end of the lead. This way you can pull the whole thing out to make it easier to solder everything. When you are ready to put it all back together, just line up the guides and rebend the end of the lead.
Lately, I have been tracing circuits in an air conditioner controller board and these ends have been helpful to clip the leads onto a small jumper wires or leads. In this case, I clipped the black lead to ground and used the bare point lead to test voltages going out to the relay card for various states. I cycled the air conditioner through high and low fan modes, and with the compressor off and on. I was able to isolate the separate wires for the fan speeds, compressor control and the beeper so I can replicate this functionality on a replacement controller board.