I have a set of these Fovno Phantom cranks just arrive too.
I notice they are different from the seller's pictures!
Mine have a dub style adjuster on the non drive side
And a tapered hex interface for the drive side crank, rather than the spline in the original pictures.
Yours look to be the same as mine! I wonder why they made the change from the spline?
Other buyers report the non drive side crank falling off! Due to the bolt working loose. Be sure to remove the non drive side bolt (its says "do not remove") add thread lock and re-torque.
Also other buyers report these axle bolts are soft - so if you have an old steel octalink bolt use that to torque the crank to the axle, then replace the alloy bolt with threadlock.
See here
http://chinertown.com/index.php/topic,2959.0.html