To quote that kid from the start of Scerbo's part on Chill Bro:
A 23t, fullguard sprocket.
I'll just let that sit in your head for a bit.
Ridiculousness. How can you make something that small, with a guard on it?!
I bet there are more out there, before people start commenting, but I just happened to spot it in the Products section, so bite me ;-)