A little warning.
I ordered extra from Amazon but I received a fake from China.
The ones being sold by third party and from China well below the retail of 9.99 would probably mean they're fake. So you've been warned.
What it's supposed to look like.
Above packaging is the original and below packaging is the fake one.
Note the stocky and short and detail-less side mechs.
Just be aware. You've been warned.