Two are certainly better in one!
Take the example of these two way closed-ended zippers on my bag:
Beside sporting a nice look, I can use either of them to store my stuff in the bag.
I may also hook up a fancy key-chain on them, something I loved to do back in my school days 🙂
So, having something in life as simple but useful as a zipper, and that too in double quantity, is certainly a blessing.
If you possess such object in your life, then make the most of it.