A lot of people have cottoned on to the fact that wireless IEM's are pointless for folk who don't use wireless for their guitar. This is the easiest and cheapest way to get into using IEM's and ironically it's the highest quality too ... because a wired IEM connection isn't susceptible to radio interference and never suffers from a flat battery.
These cables are basically a high quality guitar cable with Neutrik jacks carrying your guitar signal to your pedal board \ amp inline with a stereo cable which carries your IEM signal from your headphone amp on your pedal board \ amp back to your IEM's ... which plug into the little box you can see in the picture.
Wired for true stereo from any 3.5mm standard headphone output .... it's designed with 2 mono pots rather than one stereo because some folk like their guitar adjustable in one ear and their vocal in the other with the rest of the band spread across. Using the 2 mono pots means you have better and easier control right from your little box
Priced at £39 with delivery at £2.95 for UK Mainland