As already said, 5 gallons and nothing special about the keg other than DO NOT LOSE OR BREAK THE PLASTIC GAS TUBE!!!
The o-rings are the same as what you would use in the newer cornies and the kegs should last a long time as long as they are not damaged. What I have noticed on a few of the older ones is that over time the rubber can break down and you will get hat black crap all over everything it touches. I have read that silicone will soak into it and stabilize it.
Primary - Apfelwine
Secondary - Niagara white wine
Kegged - AH Special Holiday Ale, AH Cream Ale, AH Honey Wheat
Bottled - Continental Pilsner, Island Mist Mango Citrus, Island Mist Wildberry Shiraz
Up next - AH Foster's clone, Labatt's clone, Hard Apple Cider,
The Independence Street Brew House