Enjoy the beer that you deserve.
This is an Australian term that refers to a mid-size, pub-style cylindrical glass and is also referred to as a half-pint or pot.
Typical volume for this size of glass is 10 ounces (285 milliters).
The Middy is a mid-size version of its cousin the Pony. For English speakers, explaining the use of the name “Middy” to refer to a mid-sized serving of beer is probably not required.