This is currently the only Rebelle twin-pack. The two Sneak Attackers that are included in this blaster set have unique colors; they do not match, and they can only be found in the Power Pair blaster set.
An early version of this set, according to photos, only included black and purple Collectible Darts.
Prior to release, this blaster set was known as the Stealth 2-Pack according to early reports at the 2013 Toy Fair. Alongside several other Rebelle products, the name was changed at the last minute for unknown reasons.
It was the first method of obtaining a Sneak Attacker and the only current way to obtain one under that moniker.