Minotaur SPW10 Wireless Pocket

Great for attaching to the two part styles of guitar straps e.g. Richter Guitar Strap SpringbreakI or a Levys MS26 etc. It wouldn't fit the wider one piece straps, but I don't think that is their aim for this holder.

It is a little on the large size. My Shure GLXD1 sits very loosely in the pouch. If you move about a lot, or put on a bit of a performance with the guitar around a lot, it would most likely slip out of the pouch. The Line 6 Relay TBP12 sits in a better, with the belt clip still attached, but it's still loose. I've managed to get around the looseness issue by wrapping a velcro strap around the transmitter in the pouch.

Other than the size issue, it's good value for money.

Minotaur stuff is really well made. I have several of their padded leather straps and they are wonderful. So it made sense that when I finally got into wireless systems for my two performance guitars I went with the Minotaur transmitter holder. This thing works great for the Sennheiser XS transmitter. It's like it was made for it. It's large (from top to bottom, not width-wise) for the Line 6 Relay G30 transmitter but it comes with a width-wise velcro strap which I have used to limit the depth which the transmitter can go into the holder if that makes any sense.
Inconclusion - Minotaur doesn't disappoint. These things are built to last. But if your have a small transmitter you may consider other options.