LeBron James is firmly against a new jump-shot training tool.

A peculiar shooting technique aide got some added publicity on Thursday when LeBron James tweeted his stance on the product, QUBE.

According to the product's website, QUBE is a "revolutionary breakthrough in shooting a basketball." Selling itself as a cure for poor shooting mechanics, the invention is a literal cube, looking like a giant foam dice designed to align "proper hand placement and elbow/wrist alignment."

James wasn't impressed.

You can watch the QUBE in action below.

QUBE doesn't have James' endorsement, but the notoriety probably can't hurt. Just don't expect LeBron to bring a QUBE to Lakers' training camp in September.