Breathable ear bonnets?

[BellaBee]

I usually leave and ear bonnet off my mare in really hot weather as she gets very sweaty but isn't bothered by the flies. However, on saturday I found 5-6 huge bloodsucking flies in each ear!
She seemed completely unbothered by them but she's now got her ears covered at all times as her ears are all scabby inside and all the flies made me squeamish.

However I was riding tonight with a bonnet on her, and by the end she was visibly sweating through it, so I'm on the hunt for something as lightweight and breathable as possible.
Does anyone know of any brands that are good- preferably natural fibres or mesh/ fabric used for sportswear, if they exist?

 

[Silmarillion]

I love my Cashel ones, and they appear to be made of similar stuff to a "sports type" top I bought... if that's any help?! They are also non-fussy, which was good for my big plain-headed Irish mare!

 

[milliepops]

I use the Cashel ones too. Brilliant

 

[BellaBee]

Thanks, they look like they'll do the job. What are the sizes like? I'm not sure is she'd be a "horse" or a "warmblood". She's 16.1 but has small ears?