The correct Nerf Sports Vortex Aero Howler is the one at the link below:
It can be any color, as long as it is this exact shape and size.
It must be unmodified, except for adding your teams name to it. No devices for hanging it from your aircraft may be permanently added to it.
Painting habitats to differential them for ID purposes when dropping more than one, per rule 22.214.171.124, is allowed.
It can be purchased anywhere you prefer to buy it.
The Pocket versions are not allowed: They are smaller and lighter than the required one.
Note that many resellers use different versions of the product name and they may show different and incorrect weights that include shipping and packaging weights. As long as yours exactly matches the one in the link, except for color, it will be allowed.