One of these popped up.
Simple to install. I placed the pickup centrally behind the bridge using the adhesive pad already on it. You get one more spare in the pack too. That has a cable to a small jack you plug into a passive vol and tone unit. You can see I've clipped that easily to the instruments strap. The clip is built in. You need the provided small jack to large jack cable to connect to most amps, recorders etc. However they are easily replaced via many suppliers if that goes missing or you want a different length etc.
So £6.35, a few days waiting for it to arrive, a few mins install and we're ready to go. Now this is not an active preamp or pickup so the output level is low, but then don't write that off. Yamaha in their latest L series use a passive system which is by all accounts stonking.
So when I did plug it in to my amp yes it needs the volume pumped up a bit. I'm most likely to use it via a PA live and have a channel for its sole use so that really is no issue. Into my trusty Boss BR600 and I had to crank up the input level a bit but it wasn't bad. I mean I could get a good usable level out of it.
So demo time. Click on this link to hear a short demo recorded via my Boss. First passage is straight in, no effects or any fiddling at all. Second passage I used one of the standard Boss available effects patches. I used P81 Natural which is intended for use with acoustic guitars. I was really pleased with the results given the cost etc.