The last few times I've looked, our area CWs didn't have it, nor did their crew know what it was, which I always thought strange.
And the name is "Camco Boiler Antifreeze -100" on the bottle. Leah wants to be sure you don't confuse it with Camco RV Antifreeze, used for winterizing water systems. Adding the wrong stuff could really mess up your hydronics.
Jerry, be sure to mix the boiler fluid 50/50 with clean water before adding to the tank. You don't need protection down to -100 degrees unless you're shipping your coach to the North Pole. Our resident hydronics expert, Orman Claxton, recommended a 70/30 mix in another forum thread, though I'm not sure which is 70 and which is 30; 50/50 is easy enough for me. Keep in mind also, your tank fluid level changes whether hot or cold, so add fluid accordingly. Consider also that may be part of why you notice what you perceive to be fluid loss, though the bad expansion hose issue is apparently common and a likely culprit.

-Joel