Seems like a reoccurring question for 2a is; what string should I get? There seems to be some favorites and great recommendations, but then it boils down to what’s in stock also!
I searched the forum for info on the slackie thin for 2a but didn’t see any info, so I decided to provide my opinion as info in the off chance it helps someone.
SLACKiES yo-yo string by iYoYo – YoYoExpert
Side by side comparison is shown against the yoyofactory bulk string. Throws used are brand new Yoyofactory 720’s. These are 100% out of the box, not taken apart and no additional lube added.
The slackie provides a stronger response profile while still being a proper thin string to fit looping yo-yos narrow gap.
One thing you’ll have to watch for is that the Slackies are wound tighter. So be careful looping it into the yo-yo. Make sure you don’t get the little curl up knot on the bearing or you’ll have more response than you’ll ever want. 
