350 CCA? Unless your car is a riding lawn mower, this isn’t going to do jack.
FWIW, these sorts of things generally aren’t meant (or able) to start from a flat battery. They’re for boosting an otherwise weak battery (when there’s some life left to it - dashboard lights up, starter relay clicks, and the like).
I’m guessing they aren’t meant for anything bigger than a compact car either, because I know this thing isn’t going to touch anything with more than 4 cylinders.
It will work on a car with a battery needing a boost. My problem is that when I placed the positive clamp on the positive terminal, it snapped. The plastic clamp gave way. I had to jury rig a rubber band to hold it in place before I could use it. Right now it is useless because of the broken positive clamp. Until they make these units with more robust clamps, I could not recommend this product.