There are 2 clips with this name used by different blasters.
Monsters VS Aliens Version Edit
The Monsters VS Aliens 6-Dart Clip is a type of Non-Nerf Promotional clip that is so far only used with the Area 52 Foam Dart Shooter. It is not compatible with Nerf Darts, and instead only compatible with Monsters vs Aliens Darts. It is like the 10-Dart Banana Clip.