An All-metal Dishwasher Air Gap

Can anyone point me to where I can buy a diswasher air gap that is all metal? All the ones I can find on the market have plastic bodies and plastic mounting nuts.
Thanks
Ed

Like cast iron or stainless steel? copper? titanium? Why do you need a 'metal' one?

There is a reason why all of them are plastic. They all work well and you could possibly void the warranty if any of your home made fixes cause any problems.