It is likely due to the material (in my experience jelly-like TPR doesn't transfer vibrations too well) and because of the bullet placement. The bullet being at the joint will cause less vibration in the tips of the attachments, meaning less intensity overall.

The rating system is:

1 vroom: very mild, extremely low vibrations, great for newbies, foreplay & extra sensitive spots.

2 vrooms: A lower level intensity that provides light stimulation that can still be felt in internal and external spots.

3 vrooms: Moderate vibration, good for overall body usage, average in intensity, and probably suitable for most individuals

4 vrooms: strong and easily felt vibrations that powerfully stimulate but are not "earth- shaking"

5 vrooms: This car is outta control! Extremely strong, intense, powerful vibration that is probably too intense for most.

Now that I've said that, I chose the 1 vroom because of the position of the bullet. It just does not send the vibrations up the shafts. You can feel some vibrations at the area between your vagina & butt, which is where the bullet sits, but again, it's not strong vibrations there either.

I will say that I'm a vibration junkie, I love the earth shaking strong vibrations, and anything less really doesn't do it for me. People who don't like strong vibrations will probably like this.

I really expected more vibrations being that it uses 2 AA batteries, but I was disappointed. I think the bullet placement is the problem. If it had 2 bullets located higher, I think it would've been awesome and at least been able to feel the vibrations in both shafts.

I have the True love honey bunny which is also made of TPR, and I love its vibrations, so I'm not sure if the material had a lot to do with it or not. Bullet placement is key.

vibrating purple hippo? that sounds awesome

Agreed.