If you have ever watched dogs running thru the tunnel then you can understand why these stabilizers are needed. The tunnel would be all over the place if you did not use these. THAt would not be safe for the dog and I am sure some dogs would not use the tunnel if it rolled around.
If you do agility, then you will need these stabilizers for the tunnel.

Pros: none

Cons: none

These are a must to keep the tunnel in place.

Pros: good product

Cons: none

this is great! i think this is perfect for agility people! these will keep the tunnel in place for a bigger dog or smaller dogs to.

Pros: great, unique, cool

Cons: none

I prefer sand bags instead for the reasons expressed above.

Pros: They will stabilize a tunnel

Cons: When the ground is too soft or too hard, will not work

this is good so your dog doesnt go rolling down a hill or something

Pros: the tunnel will stay still

Cons: none