18650 LiFePo4 4S2P Battery Case

This is a case for an 18650 4S2P (4 Series, 2 Parallel) 12vdc set up. This design took most of Saturday to complete. I would print what I though was ok, only to see it wasn't and toss in the trash my failure. I'm really happy I didn't give up on this. I love the results because it fits the 18650 batteries like a glove. The sides of the case have holes to allow air to cool the battery better when it's under load. Please let me know what you think.