I flew with Control.FPV the other day. He taped 4 pennies to the top of his battery, because the extra 7 grams gave him a more neutral CoG and better handling.
That's how crazy we've come with FPV racing these days, every little edge, however small, matters "bigly" in a race. So here comes the Black Label Squares! Same awesome performance as the regular Black Labels, but in a more aerodynamically compact form factor to help you shave off precious seconds in a tight race.
Thanks to the awesome brainstorming power at RCgroups, the balance lead has also been significantly shortened so you don't have to worry about props chopping off the connector again. A balance lead extension cable is included for your charging needs.