I’ve been making cables for the Utility Plug recently. They come with the kit, but the reason for choosing these “modular” jacks and connectors, is that they are very easy to make yourself.

FYI, the 26 AWG wires in this type of cabling are rated for 360 mA current. Plenty for signaling and powering electronic stuff, but not suited for high power or high voltages.

I use the following low-cost crimp tool for most of my 4-. 6-. and 8-core cables:

Actually, I have a second one for 8-core cables (i.e. RJ-45 network cables) – it’s sturdier but also more expensive:

Here’s how the cable is made, from start to finish. First, make a clean straight cut:

Then you have to strip the outer mantle, without damaging the inner wires:

This is what comes out:

It fits perfectly into a “6P6C” RJ-12 modular plug (6 positions, 6 connections):

Now the magic part:

Seen from the other side, with the plug ready to be crimped on:

Here’s a before-and-after picture, you can see the metal pushed into the cable (and the cable jacket clamped for strain relief):

Another view:

How does it work? Well, here’s the crimp tool, in released state:

And here it is again, squeezed tight (it has a stop, ya can’t squeeze too far):

If you keep goin’ at it for a while, you get this:

And that’s where they end up at Jee Labs:

Easy. And if you don’t want to go through all this: just cut up a telephone cable instead (note that such cables will work fine, but most of them only connect the inner 4 wires, i.e. AIO, DIO, +3V, and GND, not PWR & IRQ).