Aside from its volume being measured in metric (  :-)  ) , you get a nice easy-mount bracket for it & it weighs almost nothing like Ed's Pep Boys unit.  The big advantage is, it's designed to be a sealed system without a 'burp' vessel. The cap on the bottle is the pressure cap. This means that  air pressure in the top of the tank forces fluid back into the engine/radiator as it cools.  The cooling loop is always pressurized.  Because it's translucent and part of the pressurized system, you can tell at a glance whether your system is truly full of coolant.


===>  That does sound nice.  I wonder if you can buy them new?  The 3rd gen
RX-7 AST's have a nasty habit of cracking as they get older, so I don't
think I'd want anything old, plastic, and under pressure. Now that I think about it, I restored a '65 Corvette that had a similar
sounding tank, but it was aluminum.  Cheers,
Rusty