Green antifreeze or coolant as some call it.
I took a path to simplicity. We own a Toyota RAV4. It uses a a pretty pink Asian coolant. So back when my 96 Toyota Camry had a hose burst at its little heat exchanger at oil filter I changed it to the Asian coolant. When 67 Barracuda needed a water pump I changed it to Asian coolant.
From what I understand, it's environmentally friendly, doesn't poison pets, etc...
My main reason is about having just one partial jug of coolant sitting here that I can pour into any vehicle here.
I installed a aftermarket coolant recovery bottle to B'cuda several years ago. Similar glance at coolant level under all hoods.