i know the woman who designed and produces them, she has an icelandic who has a coat like a yak and would sweat in anything which is what made her come up with the design I'll be getting one for my cob when i bring her into work as she's a sweaty bird too.
I was a 'test pilot' when Jan was first designing them and love them. I've had two now in different sizes for different equines and wouldn't get anything else.
I've got one and they're really good. Having bought breastplate type things that were a bit plasticky and fell apart, I was impressed by how well made and tough the parson's rump was.
A few people on hacks have commented positively and asked where I got them from.